Whitman Knapp was a young intern at a Canadian Hospital, who was unaware he was a mutant. He worked with Lionel Jeffries, a brilliant healer who used his mutant power of organic manipulation to help others (albeit in unethical manners, by using dead patients tissues in his work) His power mirrored the power of his brother Madison Jeffries of Alpha Flight who could manipulate inorganic matter like metal and glass.
Lionel was, however, insane, and used his powers to absorb, and lobotomise, the brilliant Roger Bochs (who was the designer and pilot of the robotic Box of Alpha Flight). Bochs' inventive mind, coupled with his Lionel's organic controlling powers allowed him to become a shapeshifting monster.
Whitman attempted to stop them, and had his entire physiology distorted by Lionel. His mouth was fused shut and his limbs were fused together.
The resulting stress triggered Whitman's mutant powers, and he reversed his disfigurement and manifested his four selves for the first time. His past and future selves all looked to the "normal" version of Knapp for guidance and direction. Despite his neophyte heroic status he helped in the defeat of Lionel Jefferies.
Knapp assumed the name of Manikin (as a pun on "Man-i-kin", since he viewed his alternate selves as kin/family) served as a member of Alpha Flight for a time, later shifting down to the training team of Beta Flight to gain more experience.
Later, following an assault by a supervillain, he lost the power to summon the other manifestations of himself, but could instead change himself into any one of them at a time.