Jack Wheeler went to college on a football scholarship. He dropped out due to an injury and enlisted in the Marines to complete his education. He quit that after most of his squad was killed by a terrorist bomb.
He returned to the Quad Cities and began taking night classes. He started dating a fellow student named Claire and fell in love with her. His new girlfriend soon began experiencing "accidents" and was ultimately shot dead in front of Jack while the pair were on a date. Afterwards, it was revealed she was secretly the daughter of a Chicago crime boss who left her family to start a new life for herself.
Claire's will named Jack as her sole beneficiary and made him a considerably wealthy man. Furious over all the deaths he'd witnessed, but unsure of how to proceed, Jack took the somewhat-facetious advice of a friend to "use the money to fight the mob". He opened up his own car mechanic/body shop as a public identity, then secretly tracked down the rival gang members who ordered the hit. He created a costume of camouflage pants, combat boots, a local college football jersey emblazoned with a snarling red dog (hiding his protective body armor), and a hockey goaltender mask to conceal his identity. Armed with a Jatimatic GG-95 PDW and a pair of electrified "shock gloves", he killed the gang leaders and the hitman who had killed Claire.
In an alternative timeline accidentally created by Booster Gold in Booster Gold #8 Wild Dog is part of a resistance cell against Maxwell Lord, being one of the only heroes still alive or uncaptured. Lord forces Wild Dog to shoot himself.
