Infinite the Jackal

Infinite is a jackal and the former leader of the Jackal Squad mercenary group, holding the title of the "Ultimate Mercenary". Infinite originally targeted Doctor Eggman before joining the Eggman Army, only to fall at the hands of Shadow the Hedgehog while defending one of Eggman's facilities. Ashamed of his failure, Infinite chose to wield the power of the Phantom Ruby not only as a means of becoming stronger, but also to abandon his previous identity.

With his newfound power, Infinite aided Eggman in expanding the Eggman Empire to its largest size to date after defeating Sonic the Hedgehog. Near the end of the Eggman War, Infinite faced Sonic and the Avatar multiple times, until he was defeated during the decisive battle for the planet, losing the Phantom Ruby soon after. Infinite secretly escaped by faking his demise and eventually met someone who showed him an Astroscopic Lens. Infinite mastered the artifact's abilites and sought to obtain the other Lenses to restore his power. However, he would eventually be defeated again by the combined efforts of Team Chaotix and their allies, though seemingly not for good.