Lucindra Thompkins is a human female martial artist who befriends and spars with Raphael. She is one of the few human characters in the series that is uniformly a better fighter than any of the Turtles.
Lucindra first appears in the short story The Name is Lucindra . Raphael calls her up for a sparring session, and since she isn't too taken aback that he's a giant Ninja Turtle, the two proceed with their kumite. Raphael loses to Lucindra (two falls out of three) and thus he owes her a Pizza.
She returns in The Violent Underground, where it is mentioned that she has been sparring with Raph for some time at that point. After thrashing Raphael once again, she heads home, failing to notice a Foot Ninja that is tailing her. After encountering a number of people, including a drug dealer who emphasizes that her brother Malcolm needs to pay his dues, she finally makes in into her apartment. The drug dealer is killed by The Foot shortly thereafter.