It depends on what you're looking for. The regal tiger is the fastest mob in the game, making travel a breeze, the beetle will let you climb up walls which is incredibly useful, and the horse...It's pretty whack. But Big Beak is the best of all worlds. It's fast and can jump high, giving you the kit of the regal tiger and a taste of Beetle. But it can also glide, which is unmatched in my opinion.