Mudpuppies are also called waterdogs and are a type of salamander. Did you know that they can make a sound? That's kind of how they got their name because of the strange sound that they can make. They aren't very attractive looking unless you can catch one smiling. I'm not sure if I would want one as a pet, would you like one?
I have never even heard of these until you make this thread. They look pretty cool, although I'd be very curious on the amount of these that are kept in an aquarium setting due to their appearance, and probably medium/high level of purchasing and requirements. Totally remind me of axolotls though.