
Black Widow in the middle.
Black Widow is a Russian spy and a S.H.I.E.L.D agent. She first appeared in the episode Deadly is The Black Widow's Bite! and started to gain attractions to her, including most of the Super Hero Squad. However, later on in the episode, it was proved that she was actually Mystique, a shapeshifter, in disguise that was working for Dr. Doom to infiltrate the Vault that held the Infinity Fractals.