Jennika, also known as Jenny, is a major character in the IDW comics Teenage Mutant Ninja Turtles.
She is a friend of the turtles, and originally worked under the Shredder as a member of the Foot Clan, which later fell under Splinter's leadership. She was later mutated into a turtle like them by, after she suffered severe blood loss courtesy of Karai. However, Jennika's intentions are not the same, also falling in love with Casey Jones.
After this she goes to live in Mutant Town where there are other mutants from Old Hob, fighting for justice.
Jennika is very tough, but also sweet and loving. She has trouble controlling her anger like Raphael, although she is better at controlling it than he is. one thing she really likes to do is listen to heavy metal music.