A man that Stucky hangs around with when in town. Both Captain Spaulding and Stucky accuse and refer to him as a "retard." Many stories and jokes of the man have been exchanged between the two as well.
Although it is evident that Spaulding and Stucky are friends, it still baffles Spaulding as to why Stucky likes to hang around Jackie, whom he refers to at first mention as "that asshole" and "that retard that hangs around Molly's fruitstand".
According to Stucky, Jackie likes to pass the time by "whacking his weasel and twisting a sharpened pencil near his eye." It was also stated by Stucky that Jackie once got a Planet of the Apes doll stuck halfway up his asshole and recquired to go to the emergency room.
Among an apparent retardation of some sort, it is also evident that Jackie Cobb is also very sexually aroused most of the time.
Although he is mentioned at the beginning scene in House of 1000 Corpses, he is never actually seen.