Ham Tyler, played by Michael Ironside, is a mercenary who becomes one of the main leaders of the resistance.
Ham Tyler (or better known in the Resistance as "The Fixer") was a CIA operative who, along with associate; Chris Farber, went on specially requested missions for the U.S. government into other countries. While on a mission in Vietnam during the Vietnam War, Ham married a Eurasian woman and had a daughter with her. His superiors promised that his family would be evacuated during the mission. But while he and Farber were sent to their target, a bombing raid caused his family's disappearance (and most likely deaths) and he never saw them again. Ham was devastated by the loss of his family and he and Farber left the agency, becoming mercenaries-for-hire.
During the First Invasion, he and Farber, join the Resistance and helped get the fledgling Los Angeles Resistance group off the ground and use proper tactics and use better weaponry. Here he forms a rivalry with Resistance leader Mike Donovan that eventually comes to a head when they disagree about when to distribute the newly made Red Dust toxin to other Resistance groups; his fighting style, strength and loyalty earned Ham's respect and gave him the nickname "Gooder". Ham coordinated the world-wide dispersal of the Red Dust in conjunction with Mike's attack on the Mothership, leaving the Earth poisonous to Visitor habitation.One year after Liberation Day, Ham has started a high-tech security agency and is hired by Nathan Bates for $500,000 to capture Diana and assist in interrogating her for Visitor technological information. This is a decision he comes to regret as this leads to Martin's death and Diana causing the Second Invasion of the Earth. Ham was disgusted by how Bates treated human life and deserts, rejoining the reformed Resistance. He continued his friendship with Donovan and became Kyle Bates's (Nathans son) mentor, giving him the nickname "Ace". During an unauthorised raid against a Visitor convoy, he was captured. Taken to Diana, he was taken to Legation and forced to undergo conversion. Using a new and improved conversion technique, visions of his missing wife and child with Donovan were used against him. Charles began planting the trigger phrase as he upped the cycles on Ham. After he was sucessfully brainwashed into killing Donovan, it was arranged for him to be rescued by the resistance. Julie tried to help him deal with his ordeal, relating to him that she had also gone through the conversion process as well. During a prisoner transfer, the phrase was used. As Ham was preparing to shoot Donovan, Elizabeth caused a lightpole to fall into him, causing him to shoot Nathan Bates instead.
He fought for the Resistance time and again and departed with Farber to escort Robin Maxwell to Chicago. In the (unaired) series finale, Ham and Farber return to help Mike's Resistance group escape Visitor attack shuttles. Ham now currently works with the Resistance to find the "Anyx", an artifact that can defeat the Visitors, amidst the destruction the Visitors wrought during the Armistice, when the Visitors took advantage of the peace to wipe out the majority of In Liberation Day When Ham is at Science Frontiers Nathan looks to a Television Feed a sees a "File Footage" Photograph of the Alien Commander Diana, Nathan then asks Ham what would he do with Diana, which causes Ham to also look at the picture of Diana, he says to Nathan that he would use Diana for target practice and when Nathan was thinking about capturing her so that Diana could assist with this universal cure for cancer Ham says that Diana is a disease.