In 2007, iibnf posted a tongue in cheek summary of the various shapes and sizes she encountered over the years:

My absolute favourite, though, was the extreme alien penis presented by Leslie Fish (Ah, Leslie, your zines are still my sugar bunny comfort fic ). Spock's genitals could best be described as a kind of hairy orchid. When he became aroused, the petals unfolded, revealing a studded (with emeralds) green shaft (again, ribbed for Kirk's pleasure!), and two little whippy tentacles that just joyfully joined in the fun.

Oh, and there was this really great novel , I forget what it was called, but it was huge, where Spock's nuts were on the inside. In fact, he may have had a couple of sets... no, wait, I remember, his nuts where accessible from the back, like, um, near his kidneys or something, so he really, really enjoyed massages, and then his scrotum just filled up with juice prior to coming. Or something. Anyway, it was hot. Back nuts.

There was one story (sadly, I never found this one, only heard about it in horrified whispers from friends) where Kirk had been raped and had developed a fear of penises (other people's, one assumes, not his own), but that was just hunky dory as Spock didn't have one. He, instead, had a hundred tiny tentacles that all sort of came together to do the job. How perfect is that? I wish I could find that story, because it's just like mini- hentai ! Hundreds of tiny tentacles ! Adorable! Although I think it would make giving Spock head an adventure in eating spaghetti. "Hey, Kirk, you want parmesan on that?"

I'm pretty sure there were a load of self-lubricating penises in the stories - because you could so totally get away with that in fandom. And why not? A self-lubricating penis is logical, dammit, Jim!

The classic fannon that was thoroughly adopted and turned up everywhere was the 'double ridged' penis . That is, Spock's glans had a, er, kind of double echo thing, another set of ridges just underneath. A subtle nod to the alien penis and the fans' love affair with same.

During the hey day of K/S fan fiction Spock's penis came in a huge array of sizes and shapes. Gayle F was the Queen of The Bells - she had Spock with a penis that came in the shape of five bells, and that will always haunt me. And yet... ribbed... for Kirk's pleasure. Hmm...

In the early years of Star Trek fandom, speculations on Vulcan anatomy were more general and centered around the differences in internal organs as revealed by Dr. McCoy in various episodes. Since Amanda appeared to enjoy a happy married life with Sarek , fans tended to assume that Vulcan sexuality did not differ significantly from human in that regard (allowing for the pon farr cycle). Humans and Vulcans could be sexually compatible even if conceiving a child required scientific intervention. [2] Even the sexually explicit illustrations in Grup revealed Spock with a perfectly normal-looking penis. It was not until fan writing shifted predominantly to K/S that widespread speculation on the alien nature of Spock's genitalia really took off. Fans imagined them to be as alien as his ears and as green as his blood. This was almost unique to Star Trek fandom [3] .

a 2011 bookmark created by WMyers from a screenshot from the episode "What Are Little Girls Made Of?"

In her book On The Good Ship Enterprise , Bjo Trimble said her husband saw the letter and understood that "they" to referred to testicles , not anything more exotic. However, fan speculation about Spock's sexual anatomy probably started with, and was influenced by the highly publicized "they," of that letter. [1]

In The World of Star Trek (Ballantine, 1973), David Gerrold wrote about what he felt to be bizarre fan letters received by the creators of the show. Among them was a missive several pages long from an older woman who very carefully explained that she was married and this was not prurient interest, but that as red-blooded creatures have pink extremities, what she wanted to know about Spock -- "with reference to particular extremities -- if they were green." Gerrold added, "Yes, they ," and added that the letter had been passed around for laughs and "idle speculation around the set had it that the particular extremity this woman was inquiring about was forked."

As early as 1972, there were fan-published speculation. In the zine Grup #1, there were articles and diagrams by fans that attempted to inform the curious about both male and female "private parts."

An Enticing Circular Motion

From Grup #1 (1972): diagrams show the "Common Movements of the Vulcan Penis During Pon Farr." Note the "rhythmic wave-like pulsations of the penile muscles" and the "lateral circular motions"

Double Ridged Penis

The idea that Spock's penis was green and had "double ridges," that is a double glans, as opposed to a human male's single ridge or glans, is an invention by Gayle F. The first appearance of these double ridges was in Gayle F's Desert Heat, the first story of the Cosmic Fuck Series, first published in The Sensuous Vulcan (1977). [5]

From the Cosmic Fuck Series: "Descending to the dark thatch where the swollen genitals lay, mossy green, engorged with blood. The double ridges on the head seemed strangely decorative. Increased stimulation? Nature had her own logic."

In a 2013 interview, Gayle said:

[6] (laughter) ... And it wasn't so alien that it would put people off even if it wasn't, you know, Lovecraft. So it was just, you know, it looked like of human except more interesting... I think everybody, everybody liked it because it was elegant... It suited him. It went with the ears so nicely. (laughter) [7] Okay. I don't remember the exact reason I picked that other than I decided I wanted Spock to have, you know, an alien cock, but I wanted it to be beautiful. And, I guess I just ran through some designs in my head, and that was a very elegant double-ridged cock that could be drawn very nicely, you know, nothing too weird or H.P. Lovecraftian (laughter) ... And it wasn't so alien that it would put people off even if it wasn't, you know, Lovecraft. So it was just, you know, it looked like of human except more interesting... I think everybody, everybody liked it because it was elegant... It suited him. It went with the ears so nicely. (laughter)

Here are a few examples of Gayle's fanart showing Spock's alien penis with the double ridges -- click on image to enlarge:

Hidden Behind a Furry Mound: The Stamen

In The Matchmaker (1985) by Janet Alyx (T'hy'la 5), Spock's penis is hidden behind a furry mound that becomes swollen and unfolds like petals of a flower and sprouts a bright green penis that unfolds like a stamen.

Let's see what it looks like, Spock,' Kirk said as he knelt, peeling the briefs over Spock's hips. He laughed softly as he surveyed the alien design. 'Almost like a woman.' Spock shivered as Kirk's fingers rubbed the soft, furred lips of the genital pouch, centered high on the pubic mound. Lips so swollen and sensitive now. Kirk's thumbs slid along the moist inner surface of the labia, parted, opened them, revealing the rounded head of the cock, a glistening green jewel framed within. Kirk's breath touched him there, moist and tickling. Spock felt the first head begin to come forth, shy, eager, responding to that delicate touch.

Great Green Anthurium & Tentacles: The Fra'ls

great green anthurium by Leslie Fish. This version included two handling tentacles which later became known as fra'ls. Artwork "A study in comparative anatomy." from Spock's genitalia, versionby Leslie Fish. This version included two handling tentacles which later became known as. Artwork "A study in comparative anatomy." from The Other Side of Paradise (1978).

In Mirrors of Mind and Flesh (1979), Kirk explores his new lover:

Other notable fanon genitalia for Spock included the great green anthurium invented by Leslie Fish in her early Kirk/Spock story Poses (1977). This version included two handling tentacles which later became known as fra'ls.

In 2008, Fish said: "I confess, I came up with that one first. My theory was that, since male mammals of temperate Earth hang their testicles out in the wind to keep them cool, male mammals of hot Vulcan would keep them buried deep inside their bodies for the same reason." [8]

A fan in 1984 said: "to my eyes it resembles nothing so much as an ear of green corn sprouting out of the center of a trillium lily." [9]

[10] [In Poses ]... there are five illos by Leslie, including a captivating one of another version of Spock’s alien genitalia. Here Spock has an “orchid-anthurium” that consists of a pouch formed by three protective petals that peel back to reveal “glistening chartreuse surfaces studded with hyper- sensitive spots of darker green, the two side-tendrils gracefully uncoiling to stand like oiled sepertine [sic] honor-guards beside the rising, proud, gleaming central shaft.” (Later these were given the fan name of frals and used in several stories.) In this version, testes in Vulcans are internally located on either side of the spine in the small of the back.

[11] There . . . there . . . I'll show you . . ." Kirk repeated, stroking steadily at the tender, changing flesh. Fascinated, he watched the three petals curl back to reveal glistening chartreuse surfaces studded with hypersensitive spots of darker green, the two side tendrils gracefully uncoiling to stand like oiled serpentine honor guards beside the rising, proud, gleaming central shaft. "Like an orchid," Kirk whispered, "or a cross between . . . an orchid and a great green anthurium . . .. Oh, it's beautiful! What are these two things for?" He ran his fingers along the wet, quivering tendrils.

In Poses , Spock explains that the fra'ls are like anchors to hold and stimulate one's partner:

Poses also describes Spock's testes as located in the lower back: "'Spock blushed. Shyly, he took Kirk's free hand and guided it carefully to the small of his back, placing the fingers two inches apart, on either side of the spine.[11]

Chenesi

Later, fandom would refer to the sort of genitalia envisioned by Leslie Fish as chenesi, a term created by Jenna Sinclair, [12] and give Spock human-looking testicles as well.[13]

From a fan in 1997:

In Vulcan males, there is another set of organs located, here and here, just below and outside the kidneys. These are the chenesi, the primary testes. They are usually inactive, except during the time of the pon farr, when they enlarge and fill with fertile genetic material... What humans think of as the balls are actually, in a Vulcan, secondary testes. These are always active; they produce the actual semen that the sperm from the chenesi are carried in at pon farr. Other than during pon farr, Vulcans are infertile, which is why their population is always a bit lower than we really prefer it to be. The secondary testes are also, as in humans, an erogenous zone in their own right. But the chenesi are an even better erogenous zone. At the proper time, stimulation of these organs is said to be one of the most pleasant sensations a Vulcan can ever experience.... The chenesi can be felt from the outside; they lie just beneath the skin in a pair of hollows, located here... During pon farr they can be felt as engorged masses; the hollows disappear and become protrusions instead. But at any time, the gentle rubbing of this area with fingers or tongue is much equivalent to the sensations a human male experiences when his prostate gland is stimulated. In other words, *very* enjoyable, indeed! [14] equivalent to the sensations a human male experiences when his prostate gland is stimulated. In other words, *very* enjoyable, indeed!

Tendrils

... she took a deep slow breath and reached out to run her hand slowly over his chest, down his lean hard muscled abdomen to his genitals, again marvelling at the slender tendrils located on either side of his penis. Usually coiled and concealed in the pubic hair, they were now unfurled, and small ripples shuddered down their length. She touched one lightly, her action eliciting a sharp in-drawn breath from Spock along with a small explosion of rapture in his mind. She stopped in wonder as the one she'd been caressing curled its short length around her hand, and with it remaining in light contact, she used that hand to stroke his penis. Again she felt the responsive tremors in his body and mind, at both her actions and her delight in giving him such pleasure. Sue remembered her first reaction to this ultimate proof of his alienness. It had been one of surprise. But he had taken her wide-eyed expression and forceful expletive to be negative, and no amount of talking would convince him otherwise. After that he had always been very careful to keep them coiled out of sight. [snipped] She was aware of his excitement spiraling higher and higher and she too was shuddering with the effort to control her desire. She slowly moved her hand away from the tendril and around to his back to guide him on top of her. She felt him rub briefly at her entrance as the tendrils positioned them selves on her clitoris, then he penetrated as she voiced a small, throaty moan of pleasure. [15] She was aware of his excitement spiraling higher and higher and she too was shuddering with the effort to control her desire. She slowly moved her hand away from the tendril and around to his back to guide him on top of her. She felt him rub briefly at her entrance as the tendrils positioned them selves on her clitoris, then he penetrated as she voiced a small, throaty moan of pleasure.

In Lois Welling 's story The Displaced (1978), a story about Spock and an original female character , Spock also has tendrils:

It is mentioned in The Displaced that female Vulcans have these genital tendrils as well, see Female Genitalia.

The Barbed "B'Yadu" Penis

The barbed Vulcan penis ("equipped with rows of rickrack which become erectile during pon farr, to stimulate ovulation" [16]) was utilized in two stories by Cardiane Wedgett: B'Yadu (1978) and A Matter of Life and Death (1979).

B'Yadu is a explicit het story in Obsc'zine #3. In it, Kirk observes Spock having sexual intercourse with a woman:

His penis was swollen astonishingly, and seemed to be growing with each thrust. Between lunges he was pulling it out of her, and then pushing back in to what must be an incredible depth. Kirk's eyes focussed, startled, unbelieving, at that massive green-hued phallus. The velvety, trumpet-shaped sheath was, as usual at such times, completely retracted, curled back against his groin. But the rest was not usual at all. The normally quiescent, tender barbs which covered the column to the tip and which always had responded so pleasantly to the touch, were no longer limp and recumbent against the organ but rose at an angle as he watched, and soon were actually bristling, stiff, turning into what looked like spines instead of soft, decorative rickracks of pleasure.

There was a pause. "I have another question." She ran a hand down his body, to brush against his erect penis. "When I first touched this, back in the pool, you were weak and barely conscious, but the spines... rose. Why?" "It is reflexive. They serve to stimulate ovulation in the Vulcan female." "Does this happen only during pon farr? No other time?" "When it is over, the barbs will...loosen, " he said, not quite answering her question. "It will not be much longer."

Internal Balls

From R & R's

Then there is internal balls. This was also an invention by Gayle F., this one in 1979.

A fan in 1984 also referred to them as "[Gayle F's] retractable apparatus." [17]

Pressing inward, Kirk could feel a rounded swelling behind the hot, moist wall... 'I wondered where you had them hidden,' Kirk murmured.... 'What do you call them?' 'The... clinical word is... s'txztiich...' Spock gasped, squirming as the fingers continued to probe the sensitive spot...Kirk laughed softly. It sounded more like a sneeze than a word. 'There is... ahhh... an affectionate term... xaha'si...' Spock whispered, '... from an ancient poem... of Surak's... to the warrior who was his first bondmate

Massive Vulcan Erection, aka Tower of Jade

[18] Spock was hung as well as any stud pony back on the farm. The human cried out into the night as the enormous cock plunged into him, his legs trembling as they struggled to hold his weight. For an eternity, the Vulcan's cock slid into him. Inch after torturous inch, it opened him, stretching him wide and causing him to beg for mercy for the first time in his life as a slave. .... And still it entered him. Deep. Deeper. Deepest. He felt Spock's balls brush against his own, felt the delicate membranes of his ass stretched until he was certain he would split open.

From Mirrors of Mind and Flesh (1979):Even those who didn't create special new forms, often 'drew' Spock's genitalia larger than Earth standard:

The massive Vulcan erection inevitably led to satires like Star Trek: The Lost Episode.

[19] ... we started reading an early story [of mine] and we were in hysterics! I had utilized almost every single “bad” writing technique known to K/S! Things such as using as many adjectives as possible and as many different ones as possible—especially synonyms for the word “big”—you can only imagine to what that kept referring! The thing is that I was so new to writing and so innocent in my first flush of K/S wonderment that I hadn’t a clue as to what might be good, or at least not so purple, writing—and I didn’t really care! I thought “towering jade pole of desire” was perfectly appropriate—it spoke to me; I could visualize it!

But wait, Spock's erection often also had a color! Enter the "tower of jade." In 1999, a fan poked fun at some of her own early fiction:

In 2001, a fan commented on a fic:

The scenes [in Sweet Surrender] are mighty hot—especially the ones where Spock administers some fellatio and where he offers himself to his master. If you’ve never thrashed on the carpet after reading a K/S sex scene, you very possibly will now.... [...] The over-all story is kind of “Deanna Gray-lite”, but who cares when you got such mad, passionate, hot, towering-jade-pole-of-desire scenes? [20] The over-all story is kind of “Deanna Gray-lite”, but who cares when you got such mad, passionate, hot, towering-jade-pole-of-desire scenes?

The Male Vagina and Self-Lubricating Parts

From Sexuality in K/S Fiction: Anal Intercourse (1985):

[21]. This certainly would improve matters for anyone fucked by a Vulcan. According to Gerry , it is unnecessary for Kirk to reciprocate because the anal passage of a Vulcan lubricates automatically. As is pointed out in ALTERNATIVE 2 , this implies that nature approves of Vulcan males being fucked even if Vulcans themselves don't. Vivienne Rivers provides Spock with the Vulcan attribute of a convenient automatically lubricating cock in " Those Who Favour Fire " ( THE VOICE 2). This certainly would improve matters for anyone fucked by a Vulcan.

Also from Sexuality in K/S Fiction: Anal Intercourse (1985):

Alexis Fagen Black's innovation in " Echoes " ( NAKED TIMES 1) is to give Vulcans internal testicles which descent through a hole located where the scrotum would be in humans. Thus Spock has a hermaphroditic quality in this story in that he can fuck and also be fucked without changing position. Both men and women can be entered through the rear, but among humans only women have frontal genital orifices. So Alexis is giving Spock a psuedo-vagina.

Circumcised?

Spock's penis, when portrayed as an essentially standard male human organ, is often shown as circumcised.

[22] Let's assume for a minute that Vulcans are physically, mechanically very similar to humans in the manmeat department. Let's assume that they have a glans, and a shaft, and maybe even visible, hanging testicles. Why in the name of glory would they have two "ridges"? Maybe they wouldn't even have one. Maybe their glans is shaped differently. Maybe they don't even have a "shaft" - maybe the business end of their member is all glans. [23] Let's talk cock for just a minute: You got your circumcised, and you got your uncircumcised. Uncircumcised, AKA "intact", "uncut", is the way nature makes 'em. It takes uncounted millions of years for nature to devise something as perfectly delightful as the uncircumcised penis, and only a few seconds with a sharp knife or hunk of broken glass to completely ruin it, OK? The foreskin is not a useless hunk of skin people, it's a very important part of the male organ, that is designed by nature to protect the penis, and facilitate smooth, friction-free fucking... Dare to dream: maybe Vulcans are too smart, too *logical* to ever start circumcising in the first place.Let's assume for a minute that Vulcans are physically, mechanically very similar to humans in the manmeat department. Let's assume that they have a glans, and a shaft, and maybe even visible, hanging testicles. Why in the name of glory would they have two "ridges"? Maybe they wouldn't even have one. Maybe their glans is shaped differently. Maybe they don't even have a "shaft" - maybe the business end of their member is all glans.

In the early 2000s, one fan wrote: