Board Thread:General Discussion/@comment-19704934-20131026233716/@comment-24204226-20140922050539

Shredder has already been both a dragon and a shark. In one of the comics' issues after he had been defeated, he came back as a shark. In the 2003 series, Shredder was a fiercesome dragon at the end of season five. That being said, the Turtles also became dragons in order to fight Shredder. It was during the whole Ninja Tribunal arc.

It would be such irony if Shredder became a rat just like Splinter.