|Origin||The Grim Adventures of Billy & Mandy|
|Species|| Human (PPGD)|
|Status|| Deceased (GT)|
|Relatives||Gladys (mother), Harold (father), Nergal (uncle), Nergal Jr. (cousin), Jeff (son), Minimandy (first cousin one removed) Milkshakes (pet), Mr. Snuggles (former pet)|
|Friends||Mandy, Grim Reaper, Irwin, Pud'n, Mindy (former), Ed|
|Enemies||Sperg, Jeff (fear of spiders)|
|Occupation(s)|| School Student (PPGD)|
Wandering Spirit (GT)
Billy is a minor character in both Powerpuff Girls Doujinshi and The Grim Tales From Down Below. Despite being a main character in his own show, The Grim Adventures of Billy and Mandy, he has only a minor role in the comics. He has only appeared in chapters 1 and 2 of Grim Tales and a cameo in Powerpuff Girls Doujinshi.
Powerpuff Girls Doujinshi
Later he was seen along with Ed collecting cookies and make a huge mountain of it and slide down of it.
The Grim Tales From Down Below
Billy was mentioned a few times during the story of Grim Jr.
He was always very weird, stupid and doing crazy things. Grim didn't know when it was Billy's time since his hourglass was very weird with twists and things like that. When it was Billy's time he was practically sinless because of his stupidity which granted him a place in Heaven, but because of his stupidity he got kicked out of Heaven and was placed in Hell instead, but his stupidity got him kicked out of there as well. Billy found his way home as a wondering spirit and went on a few adventures with Grim since Mandy wasn't Grim's friend anymore. Billy's fate was unknown after that.
Billy has a big pink nose, that he constantly picks, a small red cap, orange-red hair, a white shirt with a blue stripe, blue jeans and a pair of white shoes with a red stripe across them.
Billy is the main protagonist. He is a young happy-go-lucky child with an extremely low IQ of -5. He was outperformed by a shovel on an IQ test. He has an extremely large, pink nose, wears a blue and white striped shirt, and covers his redheaded hair with a red hat. His main affiliations are Grim and Mandy. Mandy is Billy's best friend, though she treats him more like a servant than a friend. It has been hinted several times that Billy may have underlying feelings for Mandy that even he (in his stupidity) may not fully realize. Billy is definitely kinder to Grim than Mandy is, and while he may go against the Reaper's advice and use him as a plaything, he appears to genuinely like him. Of the two children, Billy is the one who most often tells Grim that he's his "best friend".