Following a recent revelation that The Badoon are perhaps not part of the Marvel Cinematic Universe for rights reasons, the question of just what alien races are firmly established as part of the Marvel Studios films and which of them might be off with the Fantastic Four, Spider-Man or the X-Men.

That's a question that only took on more of a sense of urgency last week, when Marvel's Agents of S.H.I.E.L.D. revealed a seemingly-dead, blue-skinned alien whose existence is key to the ongoing mysteries of Coulson and his team.

Well, tonight we got a bit of insight into it, when Asgard's Lady Sif appeared on the latest episode and, presented with the mystery of the blue alien, rattled off a list of potential names.

Interdites

A humanoid race with blue skin, they have developed precognition as well as other psionic powers. They come from the planet Interdis, seventh from the sun in the Tartaru star system in the Milky Way galaxy. Their civilization was demolished by the Badoon (though clearly not in the MCU), and surviving Interdites have turned to mysticism and live like hermits scattered across the galaxy.

The image above is Wayopex, one of their mystics, at his funeral in a '90s Quasar comic. No relation to the mystical hermit Yoda.

Kree

The Kree are one of the most storied alien races in the Marvel Universe, and have given us a number of significant heroes including Captain Marvel.

The race is similar to humans, except a little bit stronger, they require more nitrogen to live…and they have blue skin.

These guys would be a pretty good place to start, since the Kree have long-standing connections to the Captain Marvel dynasty–and there’s a lot of intel pointing in the direction of a Ms. Marvel or Captain Marvel appearance coming down the line, either in Guardians of the Galaxy or in a solo movie.

Before being referenced on tonight's episode, some held that it wasn't totally clear that the Kree belong with Marvel Studios, given their long history with the Fantastic Four–but it was widely assumed as much, or at least that they’re jointly-owned like Quicksilver and Scarlet Witch.

Levians

The Levians are an alien race first referenced in a Thor comic (and their first appearance did feature Sif and the Warriors Three), so that seems like a winner...but there's not much else to indicate it would be them traveling to Earth. The race have lost their homeworld and the five million remaining members of the culture travel the universe on a massive spacecraft.

According to the Marvel Wiki, "After depleting their planet, Levia of magma and resources, the Levians sent a fraction of their race to survive their imminent destruction aboard the world-ship Levianon. The survivors continues their wasteful ways, and now live in a relatively primitive state aboard their crippled, drifting ship."

Pheragots

A semi-humanoid race with light blue skin that averages 10' in height.

The Pheragots come from the planet Arago-7 in the Arago star system in the Andromeda galaxy.

They have extraordinary superhuman strength due in part to their dense molecular structure. This might make them ideal candidates for the whole rejuvenating blood thing, but it does seem odd that anyone who can stand up to Hercules in the comics could be torn in half by something as simple as (we're assuming) a space craft crash.

That said, one of our readers pointed out that last week's episode featured writing on a computer screen that identified an event at the Guest House as "seismic activity." Maybe that crash came down pretty darn hard.

Sarks

The Sarks have only been seen once, as far as we can tell; in an old issue of Strange Tales, in which their leader -- who had powers not ordinary to his race -- did battle with Warlock and ended up consumed by the Soul Gem.

Autolycus was once leader of the Black Knights of the Universal Church of Truth, who ruled the Sark homeworld as a theocratic monarchy. He was also the Captain of the Starship Great Divide, which captured Adam Warlock. Warlock led a rebellion with the prisoners aboard the ship, which led to the battle that claimed Autolycus.

Generally, the Sarks appear in all other ways to be basically human, except with blue skin.

Centaurians

The most famous example of Centaurians in the Marvel Universe is probably Yondu, a member of the Zatoan tribe, who will appear in James Gunn’s Guardians of the Galaxy. They’re from Centauri IV, and he’s got connections in the comics to both the Avengers and the Guardians.

And, of course, in the Marvel Cinematic Universe, the Avengers are basically part of S.H.I.E.L.D., there’s the outside chance this alien could be our connection between Captain America: the Winter Soldier, Marvel’s Agents of S.H.I.E.L.D. and Guardians of the Galaxy.

Frost Giants

They aren’t always so giant, and while our boy up top looks a lot more true-blue than the whitish-greyish blue of the Frost Giants in Thor, his oddly-shaped nose and slightly disfigured mouth aren’t too far off from some of the Frost Giants we saw in that film.

These guys kind of make sense because Asgard has been such a feature in the series so far and, because of Thor: The Dark Worldand its tie-in S.H.I.E.L.D. episode, we know that the Asgardian community has made visits to earth before (and then Sif today mentioned specifically that the Frost Giants have tried to take Earth before). That could explain how this poor soul ended up under a mountain, shredded in two.