The reveal that the ninja turtles have secret siblings may come as a surprise, but this twist was set up in the show prior to its ending. In fact, this comic even shows who the fifth turtle is!

Teenage Mutant Ninja Turtles: Nightwatcher #2 written by Juni Ba, with art by Fero Peniche provides the backstory for how Jennika, the fifth Ninja Turtle, became the vigilante Nightwatcher.

IDW may have just recently relaunched its flagship Teenage Mutant Ninja Turtles comic, but there's also a big finale looming ...