Doc, played by Joel Grey, is a character in the television series Buffy the Vampire Slayer.
Doc is a Season 5 character who appears to be an eccentric old man but is actually a reptilian demon with vast knowledge of the dark arts. He first appears after Joyce Summers dies, when Spike takes Dawn Summers to him to ask how to resurrect her mother.
Later Spike and Xander Harris come to him looking for information about Glory. Doc attempts to stall for time and dispose of a small wooden chest containing information on Glory's plans. When Spike sees through this, Doc drops the "harmless old man" façade and reveals that he worships Glory. After a brief skirmish, in which his speed gives him a great advantage, Doc is apparently killed when Xander puts a sword through his chest. Spike and Xander grab the chest out of the fire and leave; once they are gone, Doc opens his eyes.
Doc later appears on the tower where Glory has placed Dawn for her ritual; with Glory occupied fighting Buffy Summers, Doc has come to complete the ritual of bleeding Dawn on his own. Spike attempts to stop him but is easily pushed off the tower. Buffy reaches Doc soon after and casually pushes him off the tower in her race to save Dawn. He is not seen again, the fall having presumably killed him.