The Icelandic Phallological Museum started as a small gag, but it's grown bigger than its creator, Sigurour Hjartarson ever imagined.

"To start with, it was just a joke, but when I realized this could be made a good collection, I intended to keep going and trying to improve it and so on," Hjartarson said in "The Dickumentary," a documentary about penises available to buy or rent online via Vimeo.

Hjartarson, 72, got a hold of his first penis when he was just a kid.

"When I was a small kid, I was given a bull’s penis as a whip, to take the cows to pasture and so on," he said in the clip above. "After I got the first, some friends of mine started bringing me penises from a whaling station nearby."

That first bull boner is a major part of the Penis Museum, which officially opened in Reykjavik in 1997.

It is currently home to more than 300 specimen penises and penile parts from more than 93 different animals, ranging in size from a 2-millimeter hamster schlong to a 6-foot whale dong.

Even after six decades, Hjartarson is still nuts over the variety of male sex organs found in the animal kingdom.

"We have 19 big families of mammals in the world," he said. "Species within eight of them have a bone in the penis. That’s something people generally don’t realize -- how many species have a bone in the limb.

"And some of the mice, it’s just a tiny -- two millimeters or something like that. With a bone of one millimeter. But it functions! And these animals are very fertile, as you know.

"So, the size is not everything, like some, well, men or women like to think."