Hiriluk was a very eccentric man, who would test his experimental medication on patients only for it to backfire, causing the quack doctor to flee. He was very caring towards others, as he tried his best to cure them, and never desired any rewards. This extended to animals, as upon meeting the wounded Chopper first instinct was to help the injured soul. Hiriluk did not back down and ended up taking on a fatherly role to the abandoned reindeer. He had a close friendship with Dr. Kureha.