Scorcher is introduced in "Hitman" when the Ice King (not knowing what a hitman is) sends him a request to hit Finn and Jake. He eventually goes away when Ice King fools him into thinking that he killed Finn and Jake. It is possible that he came from the Fire Kingdom or is a type of Djinn due to his ability to summon fire which produces no smoke. With his weapon as fire, Scorcher can also turn into smoke to sneak into tight spaces. He never speaks.
Scorcher is an extremely tall and imposing figure, roughly twice the height of the Ice King. His skin is dark red. His clothes consist of a tattered grey loincloth, headwrap, and bandages wrapped around his legs, feet and wrists. His face is covered except for his glowing red eyes.
Scorcher takes his hits very seriously. Once he accepts a job he is dedicated to completing the hit and won't focus on anything else at all until it is completed. He will only stop once the hit is complete - whether or not he is the person's cause of death. Upon completion of his hit Scorcher leaves a note which reads "Echoes of past events, nudge the tiller on my present course. I await its reflection in the future." Scorcher apparently trusts in fire to kill people; after starting a fire at Finn and Jake's Tree Fort he leaves and waits at Ice King's castle to inform Ice King the hit was complete. Once Ice King arrives and says he put out the fire, Scorcher is surprised and immediately resumes his attack on Finn and Jake. According to his hitman profile page he is "quick, quiet, and relentless." He is very persistent, continuing to attempt to kill Finn and Jake even after the Ice King insisted for him to stop numerous times (i.e. bribing him to stop). This is because money is not his motivation.
Scorcher can levitate and can conjure fire through his hands and feet. He can also turn into a mist of black smoke but the limits to this are unknown. He uses this black smoke ability when Finn and Jake are sleeping, and he starts to fly into their mouths. This could be an attempt to suffocate or poison them, but Ice King blew the smoke out of the room so the effect is unclear. Scorcher possesses extreme agility and assassination abilities that were shown when he easily took out Blastronaut. According to Ice King, he's "made out of fire. Or he commands fire... Maybe?"