Mikey was a mentally disabled Immortal who had an extensive knowledge and love for trains. Little is known about Mikey's origins; even he did not know where he was from, or when he first died and became Immortal.
In 1995, Mikey was living with an Immortal named Alan Wells and his mortal wife, Helen, at a junkyard in Greenville, Washington. When Immortal Tyler King arrived for Alan's head, Mikey and Helen hid inside an old bus and witnessed his defeat. During Alan's Quickening, Mikey panicked accidentally broke Helen's neck and then ran for his life.
It was then that Mikey met Richie Ryan, who was nearby, riding his motorcycle. Offering Mikey a ride, Richie brought his new friend to Duncan MacLeod's loft in Seacouver. Unsure what to do with Mikey, Duncan reluctantly agreed to board him temporarily. Unfortunately, King, now aware of Mikey's existence, soon traced his prey to Duncan. MacLeod stood in defense of his charge, but the sound of combat caused Mikey to panic once again. Fleeing, Mikey caused an accident, resulting in his arrest when he attacked an officer arriving on-scene.
Reluctantly, Richie realized that he was insufficient to the task of caring for Mikey. Preparing a place for the handicapped Immortal with social workers at St. Simon's on holy ground, Duncan and Richie prepared one special treat along the way. On the way to St. Simon's, Mikey was able to see to the Stanley Park Junction in nearby Vancouver, home of the Coast Starlight.
It was a moment broken by the arrival of Tyler King, and then the police. Duncan fought King, taking the evil Immortal's head. The police, however, wanted Mikey again, this time for the alleged murder of Alan and Helen. When they tried to arrest him, Mikey fought back, inadvertently killing an officer.
Realizing there was no future for Mikey now, Richie knew what he had to do. However, in a surprising burst of lucidity, Mikey stayed his hand. Pressing his neck to the side of a train track, the gentle giant gave up his life to an oncoming train, leaving Richie to accept his Quickening.
Mikey suffered from a mental disability. He also demonstrated a passion for trains.