Ultimoose is an enemy of Yin and Yang. He was a lackey of the Night Master. He once tried to make Yang give up Woo Foo forever, but failed. Another crime he committed was kidnapping the magical creatures of their world known and the Twoicorns (unicorns with 2 horns), cut off their horns and melt them down to make even bigger and magical horns. He succeeded but due to his horns being made from Twoincorn horns, he could only do good things rather than wreck havoc or cause destruction like he originally intended.
His catchphrase is "Ho Ha Hoo!" but reduced it to "Ho Ha" while trying to teach others about self-control and punches anyone who would finish the phrase, like Dave the Stump.
Ultimate Story[]
Ultimoose made his appearance in the Ultimate Story 3 spinoff, YinYangJak. He obviously became their enemy and has faced off against the trio a number of times. Although despite him being their enemy, he was seen as an insane person who likes to brag about himself and is very obsessive compulsive. Jak and Daxter can't help but make fun of this guy constantly.