9. Cosmo The Spacedog
Many casual Marvel fans likely just let out a pleasant chuckle at the sight of a dog dressed up as an astronaut inside of The Collector's collection in Guardians of the Galaxy. However, those in the know were well aware that this was far more than just a throwaway gag.
The canine in question is actually none other than Cosmo the Spacedog, a test subject for the U.S.S.R. Space Programme who was ultimately shot off into space to orbit Earth, only to drift off and end up in Knowhere later down the line.
Cosmo isn't just your run-of-the-mill stranded mutt, though. This dog actually ended up being mutated by cosmic rays during his travels, meaning he now possesses telepathy and telekinesis abilities. He also barely ages, still going strong despite first going missing in the 1960s.
Could we see Cosmo finally come into play in a big way by the time Guardians of the Galaxy Vol. 3 rolls around? For the sight of him blasting goobers away with his mind alone, one would bloody well hope so!