[Sewer Bull]

Depends on how you describe the "violent outbursts".

In "Turtles on Trial", Don got really pissed when Rocks and Bebop trashed the amphibian exhibit in the museum - his turtle pride must have been harmed with that. "Hey, did you just trash the amphibian exhibit? Oh, that does it. No more Mr. Nice Turtle," cried the enraged Don and then dropped the stuffed alligator on them. That's one example I can think of for now.