Skrull

The  Skrulls are a race of shape shifting aliens. They are extremely advance compared to humans. They are a concurring race of alien invaders. They are one of the main enemies of the Fantastic Four. They appeared in Marvel's Avengers Earth Mighties Heroes. They captured earthlings and replace them with Skrull imposters. They appeared in Marvel's Avengers Assemble as a cameo. They where in the crowd in Mojo's battle arena. Latter appeared in Marvel's Hulk and the Agents of S.M.A.S.H., they appeared as part of the concurring force. They took the form of humans in a mall wich turned out to be a Skrull space ship.