In 'Arthur', what kind of animal is Arthur Read?

What are the names of 'The Powerpuff Girls'? In 'Gravity Falls', in which state is the town of Gravity Falls located? In 'Hey Arnold!', what shape is Arnold's head often compared to? In 'Rugrats', who is the bossy three-year-old cousin? In 'Doug', what is the name of Doug's dog? In 'Blue's Clues', what kind of animal is Blue? In 'Barney & Friends', what kind of creature is Barney? In 'Thomas & Friends', what kind of vehicle is Thomas?