Donkey Kong is an arcade game that was Nintendo's first significant sucess in North America and was also the very first Mario game.
When the family finds out that Chris as made a female doll in "Encyclopedia Griffin", Peter considers it even weirder than a secret level in Donkey Kong. As Mario pursues Kong through the level, Mario's then-love interest Pauline is killed. Mario and Kong seal up the body in a barrel and roll it into the ocean, agreeing to make up an alibi and head off to the movies in support of aid alibi. Mario asks Donkey Kong if he is any relation to King Kong, but is told that it is simply a common name among apes.