Some TMNT stuff really isn't for little kids.
Perri Grey is a character appearing in Teenage Mutant Ninja Turtles Adventures Special issue 11. She is an intern at Mergenterprises, a laboratory that April investigates. Grey's boss, Dr. Koss, forbids her from giving April a tour of the facilities, but April sneaks back in when she sees one of Shredder's henchmen delivering toxic waste. April bumps into Perri (literally) once inside the facility, and the two learn that Koss is dealing with the Grem, a vile alien species.
April and Perri run, but are captured by the Grem. The two of them are locked up and mutated - April into a turtle, and Perri into a flying squirrel. The two escape their enclosure, and retreat to the sewers, telling the Turtles and Splinter of their ordeal. The seven of them return to Mergenterprises to stop Koss and the Grem, as well as restore April and Perri.
The team battles the Grem, including their mutated member, E'Vel. Perri and April spray E'Vel with anti-mutagen, turning him back, and the aliens retreat after being beaten. Dr. Koss, having been brainwashed, and Perri saw to it that he was recovering.
The anti-mutagen had been almost completely used up in order to de-mutate E'Vel, and the "cure" is offered to the Turtles and Splinter, but is rejected. April, reasoning that her friends will teach her how to cope with her new form, insists that Perri take the last of the anti-mutagen, but Perri splashes April with it. Perri says that the world would miss a famous reporter rather than herself, and that she actually likes her new form - and that she may be able to reverse engineer a new batch if she needed to.
Perri is an intern at a mutation lab, which implies some scientific knowledge. She also indicates that she may be able to use the Grem's notes to cobble together a new batch of anti-mutagen.
As a mutant flying squirrel, she has patagium, which allow her to glide short distances.
Although she is shown equipping a nightstick before leaving the lair, claiming she had used one as a campus cop in college, she is not seen with it for the rest of the story, nor is she seen actually fighting