|“||Awww, don't you wanna be my friend?||”|
Billy is one of the three title characters from The Grim Adventures of Billy & Mandy. He is the dim-witted, big-nosed friend of Grim and Mandy, and the unwilling father of Jeff. His greatest fears are spiders, clowns, and the mailman who comes by.
War Against Fuse
The PastBilly can be found in the Past at his house in his home town of Endsville. During the war, Billy adopted a Fusion Spawn named Runty, which later turns out to be his imaginary friend. Most of Billy's missions are rather pointless, but sometimes lead to more important tasks. Once Billy had the player retrieve Irwin's stuff, so that he might "watch it." Other times, he had the player collect food and cage lining for Runty, in doing so revealing Fusion Mandy's lair in the Sand Castle.
Billy gives out guide missions to players who chose Edd as their guide. He leads the player to the Crazy Brain Candy buried in The Boneyard. After this, Billy makes the player do pointless tasks like recycling his boogers and retrieving his tangelos from the Nuclear Plant. Edd has the player go to Bloo, instead when they're ready.
In his own interest, Billy sent the player out to remove the Re:Fuse posters found in Habitat Homes after being paid 20 bucks to do so by the leader of the Beautification Organization, Fusion Father. Little did he know that in doing so, he caused the local fusion monsters to return to their normal destructive selves. Due to his fear of clowns and nightmares he'd been having, Billy has the hero go south to City Point, in order to defeat the Destroyusalls. He then has them collect their noses, but thinks the noses are scary, so the hero gives the noses to Bloo.
Billy also tricked the player and stole their power of destiny, which allowed them to activate totems, just because he thought it was cool. Soon following Billy's attempt was Hex, who was unaware that Billy already had stolen the player's power. However, Mandy gives the player the Pillow of Common Sense, a strange pillow that actually took back the player's ability from Billy when the hero smacked him with it, and Mandy returns the player's powers to them (saying that she COULD have kept the powers herself, but decided she already had common sense).
Fusion Control Center
In the last attack on a Fusion Control Center, Demongo planned to have Eduardo join the hero to provide an assault of Imaginary Energy. Billy showed up instead, thinking that the Control Center was the site of a party. He later showed up in Fusion Kevin's base under the same delusion. This time however, he was able to make himself useful by overloading a force field made from Imaginary Energy stolen from Foster's Home, allowing the player to defeat Fusion Kevin.
Billy's Nose and a pair of shrunken heads modeled after him are possible drops from defeating fusion monsters.
- Billy is one of three characters in the game to have created an imaginary friend, the other two being Mac and Dee Dee.
- He's the only character who appears in four lairs.
- In "Beautification Mutation (Part 1 of 6)" Billy notices that when you take off a Re:Fuse Poster, another one takes its place. This is a reference (As well as a fourth wall break) on how you can't actually take off items in FusionFall.
- The Nano Power "Inner Frat Boy" is a reference to the Billy and Mandy episode "Attack of the Clowns". In the episode, when Billy goes into his happy place, he talks with his imaginary "Inner Frat Boy", who turns his fear of clowns into a hatred of them.
- Billy is voiced by Richard Steven Horvitz, who also voices Billy's Dad, Rodney J. Squirrel of Squirrel Boy, Grey Matter in the original Ben 10 series, and Zim of Nickelodeon's Invader Zim, among many other characters.
- On July 22nd 2019, Billy received a new character scale in Retro Beta Patch 2.9.
- During the Fuse Some More world nano mission, Billy refers to 'Fusion Runty' as 'El Gran Gordo', which is roughly 'The Big Fat' in spanish. This is a reference to the Sonic X comics, where Eggman took on that name as an alter ego.