Code-named Grizzly due to his massive size and bestial appearance, mutant Theodore Winchester used his skills as a mercenary. Over a decade ago, Grizzly was recruited into
Cable (Nathan Summers)'s
Wild Pack along with
G.W. Bridge, Domino (Neena Thurman), Hammer (Eisenhower Canty) and
Garrison Kane. AIM (Advanced Idea Mechanics) employed them to retrieve a stolen fiber ionic fibrillator from a New Mexico
Hydra base. Unbeknownst to either the Pack or Hydra, the device was a decoy AIM allowed Hydra to steal to gauge the progression of Hydra's EMCHAC (Energy Matrix Channeler and Converter) machine, which required the fibrillator to function. The Pack teleported away with the device before Hydra leader
Baron von Strucker remotely destroyed the base. Paid for their services, the Pack separated until Cable reunited them again. The Pack was later hired by
Tolliver (secretly Cable's time traveling son, Tyler Dayspring) to destroy a corporate building in Tehran, Iran, which they did under the guise of rescuing hostages from local militants. A few years later, Tolliver again hired the team (now called the Six Pack), sending them to Afghanistan to eliminate Russian interference in Tolliver's illegal trade route. The Pack located a secret instillation where Cable's clone
Stryfe's forces, the Pack teleported away before Stryfe destroyed the instillation. Their reputation damaged for this failure, Tolliver sent other mercenaries after them, which the Six Pack spent months fending off. Cable convinced the Pack to join him in raiding Stryfe's base in Uruguay, during which, Stryfe captured Kane, demanding the return of a disc Hammer had downloaded from Stryfe's computer records. Desperate to save his friend, Hammer agreed and tried to give the disc back, but Cable, who believed Stryfe's elimination outweighed Kane's safety, shot Hammer in the back; Cable teleported away alone to pursue Stryfe, leaving Grizzly and the Pack to fend for themselves. With Cable gone and Hammer paralyzed, the Pack disbanded.