So it was said that there was one last hidden Easter egg within the cosmic Marvel movie, Guardians of the Galaxy.
I hope you remember the rumor that Taneleer Tivan was holding Beta Ray Bill in one of his containment boxes. From this little picture.
WARNING: This is just a theory. So please bear with me.
At first I thought that it could be Thor. Which is further explained in my other post. (Before I really thought about it)
I believe that this is Odin.
Back when Thor: The Dark World came out. We all gazed in awe as we knew our favorite trickster was alive. But to take down ODIN?? Now that was sly. But those who have read the comics, knew that was coming. So what happened to Odin?
The team who wrote and filmed the movie did say that Odin wasn't dead. I mean, he is the "All-Father". Only Fenrir is known to have slain the god. (Fenrir is a monstrous wolf that eats Odin in the Norse apocalypse myth known as Ragnarok)
Well, remember the mid-credit scene? When Lady Sif and Volstagg deliver the Reality Gem to Taneleer Tivan? I believe that Loki also left Odin in the hands of the Collector. Insuring that the deal would be kept, if the Reality Gem was given as payment.
A theory that is a little "out there". But I think that it would make sense. Again, this is all just a theory I came up with. Only James Gunn knows the final Easter egg.