William (also known as Billy) is a character of The Grim Adventures of Kingdom Hearts. Billy is a boy who lives in Endsville, is kind and very stupid. Billy often causes trouble for the city of Endsville and for his friends, Mandy and Grim.
Billy is a happy-go-lucky, hyperactive idiot. His curiosity leads him into all kinds of trouble and he believes that the Heartless are innofensive pets.
He appeared by first time in "Grim & Evil" (2001)
When Sora meets Mandy and Grim, Billy runs up to they to show his new pet, Shawdy. A Heartless that he caught thinking he was innofensive. After that, Sora tries to destroy Shawdy, but Billy takes the Keyblade to play, accidentally throwing it to Victor.
After the attack of heartless, Billy follows Shawdy and other heartless when they steal the Grim's scythe. When Skarr is prepared to fight, Billy hides behind Grim.
Finally, Billy says goodbye to Sora, and after his departure, Billy wonders where is Shawdy.