He alternated places with the real Patrick a few times in Seasons 4-5 but officially replaced him in Seasons 6-8. In Season 9 the real Patrick returned and Patjerk and Patrick were required to alternate places like in Seasons 4-5.
He has a romantic relationship with ScumBob SnarePants. His first appearance was during a scene from "The SpongeBob SquarePants Movie" (2004) in the David Hasselhoff scene when SpongeBob and Patrick told a bad joke. He occasionally likes to torture ScumBob because he doesn't have anything better to do with his life like rubbing a Mermaid Man and Barnacle Boy card in his face by destroying it.
He is dumber, meaner and more cuntish than the real Patrick and appears to be a big, big bully. He also has trouble opening all types of containers. The reason for this is unknown. However, he blames Patrick Star. He also likes to fight over stupid toys with ScumBob and doesn't know how to share or doesn't even what sharing is because he is a prick.
The most noticeable difference between him and Patrick is that Patjerk's front tooth is showing for the majority of the time, whereas Patrick's is barely showing up at all (except for a few rare occasions in Seasons 2-5).