Screwball is a pedophile who lives in Joseph's house. He disguises as a clown. He makes snake balloons and sells "candy", which is actually meth. He appears to love children in a weird way. He attends Bowser Junior's sixth birthday party, along with Joseph, and makes snake balloons for Bowser Junior and his friends. Screwball is good friends with hansel. In the SML movie trailer, Screwball is the secondary antagonist, as he is seen driving the ice cream truck and kidnapping either Jeffy or Mario.
In Bowser Junior's Halloween, Screwball is seen in a box. He doesn't have any candy but instead offers leftover rocks from his "Rock Party" to Junior, Joseph, and Toad because he recently had a rock party. Cody receives a used condom and its wrapper, as Screwball did not have any rocks left. He offers Junior and his friends to go in his box. When Junior and his friends leave, Screwball announces that he loves them.
Screwball is a funny and sneaky clown who is pedophilic, necrophilic, creepy and sometimes evil.
Some characters do not believe Screwball exists due to his name (such as Bowser's Mom and Black Yoshi, albeit they never met him)
In Bowser Junior's Halloween, it appears that Screwball does not know Junior and his friends and that Junior and his friends do not know him, despite having met each other in earlier videos.
Screwball is named after a clown who visited Logan's birthday party when he was young.
Screwball was actually originally intended to kidnap the kids in Bowser Junior's 1st Grade! Part 5, which would've caused the school to shut down and everyone pass by default, but Logan decided not to go down that route.
Screwball believes that meth is candy.
Screwball has gone on dates with Joseph's mom multiple times, despite the fact that she's dead.
Despite Screwball having weird actions, the kids and adults in the SML Universe never notice any of his strange, illegal, or perverted actions.
Screwball's character may have taken inspiration from notorious serial killer and rapist John Wayne Gacy, known for acting as a clown for parties, parades and events. Except Screwball doesn't kill people.