Gary and Karen are a separated couple from prehistory. In "Jungle Love", Stewie Griffin mentions that his parents Peter and Lois are not the first couple to have problems. Karen is then seen confronting Gary, who just returned from hunting, about his pornographic drawings. After a long argument, where it is revealed Gary wishes Karen would look more attractive, Karen packs up and leaves him, to which he angrily insists her to do. After Karen leaves, Gary yells at a nearby couple witnessing the dispute.
Gary and Karen also appear in a cutaway by Brian in "Yug Ylimaf" when he points out that some men have moves. Gary simply tells Karen "You, me, sex."