Haiyama's Digital Pet was a Gold Star Pet. Haiyama abused it in his thirst for power.
Haiyama tried to take Hiroto Honda as his pet. After he whipped Honda unconscious, Dark Yugi appeared and challenged Haiyama to a Digital Pets Game of Darkness. Yugi's pet, U2, used data it incorporated from a data exchange with Joe to power up. As his pet began to fail, Haiyama proceeded to whip it. As a Penalty Game, Haiyama was put under the illusion that his pet turned against him.