"If this Pokémon is flying by fluttering only a pair of wings on either the forelegs or hind legs, it’s proof that It has been flying a long distance. It switches the wings it uses if it is tired."
Crobat is one of a long string of Pokemon that are extended evolutions of Pokemon we've met in the Kanto region. In this case, Crobat is the evolution of Golbat. In the anime, Brock gets his Golbat to evolve into Crobat, and it becomes a very powerful Pokemon on his team.
Crobat's Basic Moves are Air Slash and Bite, while its Special Moves are Sludge Bomb, Shadow Ball and Air Cutter.