Chukka is the personal bodyguard of Gilbert Bates. He is the only Ogre who can be recruited. After the Living One has investigated the Black Mountain Clan on behalf of Bates and agreed to travel to the Isle of Despair, Bates will potentially offer the services of Chukka, just once, provided the player meets all the criteria of having him join. This requires a relatively high charisma and a good alignment.
Chukka is a powerful melee fighter, but he's also good-aligned and will take offense if one performs any evil deeds.