Cheetah

Origin: In the comics, Cheetah is merely a woman in a cheetah costume. In Justice League, Barbara Ann Minerva is a genetic scientist who was about to lose her funding so she used herself as a test subject.

In Injustice for All, Batman manages to manipulate her onto his side. The Injustice Gang finds out, and "kick" her out of the gang.

Comments: Once again the creators of Justice League manage to put thier own creative twist on a classic character. Cheetah doesn't seem to up the the League's power level though, so it's natual to put her in with the Injustice Gang. Interestingly enough she doesn't make it into the follow up episode, Fury eventhough she's a woman and a Wonder Woman villian. Perhaps she's still recovering from the beating Grundy gave her.