Nellie and Thomas McElroy
Nellie and Thomas McElroy were the parents of Chef and are both voiced by Trey Parker. They first appear in the episode "The Succubus", when they come to South Park for Chef's wedding. They appear later in the episode "The Biggest Douche in the Universe" when Chef takes Cartman and his mother to his parents' manor house in Scotland. They perform a shaman-esque ritual to exorcize Kenny's soul from Cartman's body. In "Red Sleigh Down", they are seen in a crowd during the town's Christmas celebration. They are not seen at Chef's funeral in "The Return of Chef".
The McElroys' main subject of conversation is their supposed encounters with the Loch Ness Monster. They repeatedly claim that they have seen him on multiple occasions, and are constantly harassed by him, as he tries to swindle them out of "tree-fiddy" ($3.50). According to Thomas, the monster has pretended to be a Girl Scout, an alien, and Chef's imaginary friend from childhood.
Read more about this topic: List Of Recurring South Park Characters