Tigra

Greer Nelson (née Grant) formerly worked as the costumed vigilante known as the Cat, enhanced by Dr. Joanne Tumolo who gave her cat-like powers tied to her costume. She was later mutated into Tigra, a Human/Tiger hybrid, created through a mystic ritual that bound her soul to one of the Cat People, a race of humanoid cats created during the Middle Ages. Powered by the Cat's Head Amulet, she can transform from her human form to Tigra, and became the Cat People's champion. She was later recruited into the Avengers and became a prominent member of the Earth's Mightiest Heroes.

Tigra possesses tiger-like abilities to match her tiger-like appearance. She has razor-sharp retractable claws on her hands and her feet, which are strong enough to cut through steel. She possesses heightened senses and night vision. She is able to detect someone's mood swings merely by scent, and can see farther than a normal human with high-powered binoculars could. Class-10 super-strength, allowing her to to lift up to 10 tons under normal conditions. She possesses incredible cat-like agility and reflexes. She is able to jump at least 40 feet with one leap. Super-speed, being able to run up to 70 miles an hour. Strong empathic skills, allowing her to immediately detect even non-visible injuries like internal bleeding or broken ribs. Has a minor healing factor. Tigra also has a slight resistance against telepathic attacks. She is able to communicate with felines. Tigra is able to dislocate her joints to escape entrapment. Tigra has been intensively trained in hand-to-hand combat by Captain America, and also has full police training. She is a skilled pilot and can fly spacecraft as well as the Avengers Quinjet. Being a former private investigator, Greer Nelson is a talented detective and tracker.

Being naturally coated with warm fur, Tigra has little need for clothing and finds it uncomfortable and restrictive. For modesty's sake she wears only a black (sometimes dark blue) bikini, decorated with animal claws in the tradition of the Cat People. On the front clasp of her bikini top is a mystic amulet shaped like a cat's head, given to her by the Cat People, that allows her to transform her appearance from feline to human at a touch. However, she now greatly prefers her Tigra form and only changes to human form when absolutely necessary.

HYDRA was an authoritarian-subversive paramilitary terrorist organization bent on world domination.