Mrs. O'Neil (clone)

Mom Thing is the name given by Raphael to the creature that pretended to be April's mom in the 2012 TV series.

History
Buried Secrets - The turtles find April's long-lost mother frozen in a Kraang ship buried under the farmhouse, though it's not really her it's a kraang-human hybrid with Mrs. O'Neil's memories, Raphael called it Mom Thing as a nod to John Carpenter's The Thing.

Trivia

 * She's voiced by Renae Jacobs, who voiced in the 1987 TV series.