Leatherhead debuts on TMNT, a real-life Hobbit One Ring, plus a Rugrats

This week in the world of cartoons, a familiar face appears on Teenage Mutant Ninja Turtles, a new character debuts on My Little Pony: Friendship is Magic, and we've got a couple of holiday-themed clips for you as well. » 12/15/12 7:00am 12/15/12 7:00am

Top image courtesy of Nickelodeon. airs Saturdays on The Hub. airs…