Kevin Spencer (⁠o⁠´⁠･⁠_⁠･⁠)⁠っ

Kevin Spencer is described as an alcoholic, chain-smoking sociopath with multiple mental disorders (most notably attention-deficit/hyperactivity disorder and antisocial personality disorder, as well as psychosis). All of this contributes to his failure to make friends or integrate into society. His personality is described on the archived, though now unavailable, page of the official Kevin Spencer website (as of June 2024, only one image was available on the site):

Kevin is a full-blown sociopath, addicted to cough syrup and cigarettes. He is primarily guided by emotions and acts to satisfy his immediate needs and desires without regard for future consequences. Kevin has little patience for the world at large and has simplified his life to the pursuit of a few basic needs: more cough syrup, alcohol, more cigarettes, and "fixing things." However, beneath this exterior lies a sympathetic antihero who is only trying to defend his small right to the world. Kevin's only wish in the world is "just to fit in." Despite his endless failures in this pursuit, he keeps getting up and trying again.

Allen the Magic Goose ("imaginary friend"/creator) Percy Spencer (father) Anastasia Spencer (mother) Phillipe Spencer (first cousin) Michael Jackson (first cousin) Lester Spencer (uncle; possible father) Ollie (pet, deceased) Bradley Depalma (twin brother) Pete Wilcox (friend) Timmy McNaughton (acquaintance, friend) Shawna (love interest) Lisa (ex-fiancée) Mr. Franklin (hates) Grandpa Spencer (grandfather) Grandma Spencer (grandmother) Great-grandfather Spencer (great-great-grandfather)

Kevin is a pale-skinned teenager who almost always wears a black baseball cap; underneath, he has short, shaggy black hair that frequently changes length and style. He wears an orange V-neck sweater with a black pocket on the right side, blue jeans with dark red pockets, and black boots.

Kevin lives in a messy and neglected house with his parents, Percy and Anastasia Spencer, both of whom are alcoholics and often neglect his well-being. Kevin has a twin brother named Bradley, who was adopted by another family at birth, simply because Kevin has shown no emotions since birth and, according to Percy, "would have been easier to deal with." Kevin has mixed feelings towards his parents, meaning that he doesn't care whether or not they get hurt in any prank he gets up to.

It has often been questioned whether or not Percy was her real father, although there are certain implications given by the show that strongly support the idea that it is true.