Unkajo was a result of genetic experimentation by the NightsisterKyrisa, who had crashed on Hoth after being exiled from Dathomir by Clan MotherGethzerion. Kyrisa had mastered the power of Animal friendship and could exert and maintain control over large groups of beasts during the extended periods of time and over great distance.
Around 2 ABY several parties came to Hoth looking for Kyrisa, including a group of ISB agents sent by Blackhole. Unkajo and several smaller common wampas attacked the Imperials during their planning session, forcing them to defend themselves against the vicious animals. After the smaller wampas were dealt with, all efforts were concentrated on taking down the giant Unkajo. Hamstringing the huge wampa limited the range of its deadly claw swipes, and eventually it tired enough that one soldier could deliver a finishing blow. After the battle Kyrisa herself revealed her presence to the group from across the ridge. Furious at the defeat of her pet, she ordered a pack of Hoth hogs to attack the Imperials.[1]