Rebjørn

Rebjørn is a bonus party member in Dragon Quest V. He is only available after the game is completed. He is a reincarnation of Bjørn the Behemoose and has great power. You can find him by going to the pot where Bjorn was sealed after completing the Stark Raving T'N'T Board. You first find him at level 1 but if you level him up enough he can be very powerful.