|Butt Knocker KPopp|
|Name||Butt Knocker KPopp|
|Parents||Kelly KPopp and Cornell Riffin|
|Traits||Artistic, Kleptomaniac, Coward, Hates the Outdoors, Excitable|
|First appearance||Episode 11|
Butt Knocker KPopp is Kelly KPopp's eleventh child, and the twin brother of Cinderblock KPopp. He and his sister are vampires, they are Kelly's only vampire children. KPopp didn't always remember he was a vampire and ridiculed him for his pink hair.
Once, when he was a child, Kelly couldn't access her online dating profile as Butt Knocker was playing on the chair.
When KPopp started the Baby Farm she considered adding a KPopp son and impregnating the whole town. The first one she came across was Butt Knocker, but the family was full. After kicking someone out, she chose a different KPopp son instead.
He finally returned to the KPopp household in episode 47, but he appeared to be miserable due to his fear of the Bonehildas. He also hates the outdoors so when he runs outside of the house away from the Bonehildas, he soon goes back inside again. It is even worse than when Anorexia KPopp was scared of the Bonehildas.