Sacred Haven of Debauchery

I'm currently playing through Teenage Mutant Ninja Turtles 3. I dealt with Rocksteady; there was also some fat guy on a ship, and then a clone of one of the turtles. Anyway, I got to Bebop, but I can't beat him. After that, Shredder should appear, followed by a human character from the Turtles. I heard somewhere that there's also a super Shredder later on.