Mister Y

Mister Y is an alias used by a fictional government operative featured in the FOX Network television series The X-Files. Played by actor A.C. Peterson, he first appeared in the premiere episode of season eleven titled, "My Struggle III". Actor Alexandre Campion played young Mister Y in flashback scenes in that same episode.

Biography
The man known only as Mister Y, was a grey-haired middle-aged Causcasian man who wore a short ponytail and smoked cigarettes. He was a former member of a powerful global entity known as the Syndicate. Mister Y played a major role in an ambitious agenda to colonize space. Along with Erika Price, Mister Y turned against the objectives of their colleague, C.G.B. Spender, who had intended on releasing the Spartan virus on the entire world.

When Fox Mulder came to Spender's South Carolina estate, he found Mister Y and Erika Price instead. Mister Y told Mulder how they were acting against the efforts of Spender, who was Mulder's father, and tried to coax Mulder into removing this particular problem from their lives once and for all.