Some TMNT stuff really isn't for little kids.
Fluffy Brockleton, an anthropomorphic dog, is a character created by Michael Dooney for his Gizmo comic book series. His best friend and partner is Gizmo Sprocket, a robot with a cool attitude. They are accompanied by Soto, a sentient, pan-dimensional space vehicle that resembles to a trailer truck.
Involvement with TMNT
A two-issue mini-series was produced in 1989 called Gizmo and the Fugitoid, which was written by Dooney and Peter Laird. Fugitoid himself was a crossover element to the TMNT with from his own story in Gobbledygook. The Gizmo and the Fugitoid story takes place following Fugitoid's story arc in Eastman and Laird's Teenage Mutant Ninja Turtles volume 1.
Fluffy is former military, as shown in a short story featured in Mirage's "Grunts".