This is the only time in the X-Files series that the Alien Bounty Hunter shows his true alien face.
Mulder is Chris Carter's mother's maiden name. Mulder's first name, Fox, is the name of Carter's childhood friend. Scully is the name of the LA Dodgers' sports announcer Vin Scully, to whom Carter listened as a child. The voice announcing the Dodgers game is none other than Vin Scully.
The character Josh Exley is based on Josh Gibson of the Homestead Grays, A.K.A. "the black Babe Ruth," whose jersey Mulder wears at the end. Gibson died in 1947.