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 the first issue of his limited series, he barges in on a hostage situation and kills all the criminals. He successfully rescues an endangered TV news reporter and is named “Wild Dog” after the SWAT captain orders his men to shoot the vigilante “like a wild dog in the street.” His actions in the beginning are mainly directed against domestic American terrorists led by the “Committee for Social Change”. He faces other threats, like a social group, the National Legion for Morality, willing to use arson to destroy pornographic material.
Wild Dog changes opponents when he becomes a small part of the effort to resist an earth-wide alien invasion. Later, the alien Lobo is sent to New York to kill the comic book editor Mike Carlin. Wild Dog is one of many recruited to stop Lobo. This group includes Black Condor, El Diablo, Garryn Bek, Human Flea, Strata, Velvet Tiger, and Wotan.
Wild Dog was next seen, alongside the current Vigilante and the current Crimson Avenger on a Metropolis rooftop. This group, joining in on a hundreds-strong effort to protect the city from the Secret Society of Supervillains, is seen raining bullets down on the Trigger Twins, Madmen, and other villains in Infinite Crisis #7.
In an alternate timeline accidentally created by Booster Gold in Booster Gold (vol 2) #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.
A gang named the Wild Dogs, patterned on Wild Dog, appears in Green Arrow #18 (2017), following DC’s The New 52 and DC Rebirth continuity-changing events. They are described as a libertarian militia “inspired by some nut in the Quad Cities” and attack the Native American settlement where Arsenal’s old foster family lived. They are swiftly shut down by Green Arrow.
Jack Wheeler returned as a supporting character in Cave Carson Has A Cybernetic Eye, a 2016 Young Animal series written by Gerard Way and Jon Rivera.