I think tortoises are starting to get a little angry that they're known as the slow animal and everyone picks on them for losing to the hare.
Don't believe me? You'd think a full-grown Boxer dog would be able to beat out a tortoise in "who's more scary," but this video says otherwise:
Homeboy is bucking at Whiskey [which is officially my favorite dog name ever, and I'm not even a whiskey fan] and making the dog run away! WHAT?!
I would say pick on someone you're own size, Mr. Turtle, but he clearly can handle much bigger. No more Mr. Nice Guy.