|Whatever life holds in store for me, I will never forget these words: "With great power comes great responsibility."
Spider-Man has declared that this article is still under construction.
Jeffrey "Jeff" the Spider is a giant Underworld spider and the supporting character in The Grim Adventures of Billy & Mandy and one of the main characters in the TV movie Billy & Mandy Underfist: Hallowenn Bash. He is a giant Underworld spider monster. He is the son of Billy and Mandy. Jeff made his first appearance in season 2. In Underfist, Jeff sings "I Don't Wanna Grow Up" with Fred Fredburger.
He was voiced by the series creator Maxwell Atoms.
Jeff is an gigantic spider that Billy hatched from an egg who quickly imprinted on Billy. Later tried to "grow up", with mixed results, and joined Underfist.
Jeff is an giant spider with a heart of gold and no desire beyond to be loved by his adopted father, Billy. In fact, he is described by Mandy as being both "too nice" and "basically insane". However, Jeff seems completely incapable of understanding that Billy hates spiders, including Jeff himself, to the point of madness, despite the fact that Billy regularly beats him with anything he can get his hands on. His only real goal in life is to really have Billy love him like a son.