|Keith Knudsen Senior|
|Name||Keith Knudsen Senior|
|First Appearance||Shame on Pee|
|Voiced By||Ken Marino|
Keith Senior first appeared in the episode Shame on Pee, where he had high expectations for Keith's birthday party and wanted it to be a huge hit and make it onto the local news channel. Hoewever, he thought that everything about the party was going to fail because all of the things about it were completely mediocre. His exact worries came true, when the party happened and no news channel would record it. Keith Senior showed Keith his penis, which apparently looked like a "partially chewed honey comb", saying this used to have been his biggest disappontment, but then, it was replaced by Keith. He was going to give him a wheelbarrow full of cocaine as his birthday present, but he took it back. He was later seen, filling out adoption papers, to replace Keith with an orphan child named Alistair, but just then, the party made the news and he restored his faith in him again. Unfortunately for him, he had already snorted all the cocaine so his present was the empty wheelbarrow. Later, when people were defeating the Shomoculus by shamelessly telling their darkest secrets, Keith Senior told his secret, which was about his tiny honeycomb penis, that he mentioned earlier.
Keith Senior returned in the episode On Golan Pond, where he and the other members of the Knudsen family came to their own private cabin while the Beekler family was there and had a huge party. Keith Senior's log cabin was this very luxurious and opulent cabin with a built in hot tub that had a flat screen TV installed at the bottom. Nothing about what he was doing was safe as three electricians died of installing that. He also did other unsafe things like shooting loaded guns around, swimming in lakes full of leeches, and launching T-shirt cannons, filled with bees, endangering the lives of both of their families. Keith Senior had high expectations for Keith, wanting him to have sex with Alexis, during their visit. He told him that he had better come back chafed, or never come back at all, putting a lot of pressure on Keith to have sex with Alexis. He ended up dry humping her, unintentionally, by getting trapped in a snare and trying to shake their way out. which helped him win the respect of his father. Meanwhile, Keith and his wife Go Go had a party at their log cabin with Carole, while the kids, teens, and demons were away and played a lot of party games such as truth or dare and drinking games. Keith Senior showed them that he had a robot named Party Bot, who was a robot, built for partying, who also found love with Carole. However, he was going to turn him in for a newer version, so he and Carole ran away with each other.