(Covers information from Anderson's universe)
The Axeman is a mutated Undead in Resident Evil: Afterlife and Resident Evil: Retribution. The monster is a recreation of the Executioner Majini from Resident Evil 5, a lone Axeman (which was probably the original before Umbrella started cloning) serves as the tertiary antagonist of the fourth film and two cloned Axemen serve as minor antagonists of the fifth film.
The Axeman first appears in the streets of Los Angeles, dragging its massive axe behind him. Eventually, it arrives at Citadel Correctional Facility compound where Janus and the other survivors have taken refuge. His presence appears to excite the other Undead as they attempt to breakdown the door. Claire Redfield and Luther West try and fail to barricade the gate. The Axeman breaks down the main gate, allowing hordes of Undead to infiltrate the facility.
Its whereabouts are unknown until the group attempt to use the tunnels created by the Majini Undead in the shower block. It kills Kim Yong, splitting him in half, and renders Janus unconscious with one blow with the flat side of its axe. Claire is left to fight the creature on her own, barely dodging its attacks until she outsmarts him. He is rendered momentarily unconscious when Claire slides between his legs and fires Janus's shotgun on him at close range. He regains consciousness and throws the axe at Claire as Janus arrives in time to pull her out of the path of the weapon. One final blast to the head with her shotgun obliterates the Axeman's head completely.
The Axeman returns as part of the New York test scenario in Umbrella Prime. Ada Wong and Janus Prospero, after escaping from the Umbrella command room, are ambushed by two Axemen in the scenario dispatched by the Red Queen. Both Axemen are killed when their weapons become lodged in the frame of a taxi cab in an attempt to kill Janus. Ada and Janus dispatch the pair by shooting the gas tank which causes an explosion strong enough to kill both creatures.
Strength and abilities
The Axeman is faster than he is in Resident Evil 5; he is able to swing his cumbersome weapon much quicker and run after his prey while swinging his axe at the same time. However, his endurance is weaker and though he can withstand small caliber shots from a handgun, he cannot be killed with a single headshot like common undead. It seems to get killed only by suffering massive body damage (like an explosion) or losing his own head.