Chopper. Not only can he fight, but he's a pretty good medic to boot. So fighting plus can treat you when you get injured....Yeah Chopper. Now if it were between Chopper and Gajeel's cat (I forget his name at the moment) then maybe the black cat.
Ironic coming from the person who spelled English and sucks wrong. Also there is nothing wrong with that sentence, though the word "he" could have been added between "and" and "can" but it doesn't affect the sentence any.