Accidentally
The leader, Master Splinter (the rat from Ninja Turtles) isn't even supposed to exist. He exists because someone accidentally poured ooze on him.
ぐう
たま
None
But really, if you do something accidentally, it's probably a good (ぐう) thing in a way. You learn a bit about how you can improve yourself so you don't do it again, or in Splinter's case, it's just a good mistake!