Kilgharrah, the Great Dragon is a character from the BBC's television series, "Merlin". He acts as a wise counsellor for the title character in dire situations. He was imprisoned under the palace long ago by Uther Pendragon, Ruler of Camelot and father of Arthur Pendragon. He is voiced by John Hurt.
He appeared in "Excalibur" where he appeared in the island of Avalon and led Terrence Silva and his grandfather, Sirius Black, to the legendary blade. When Sirius was kidnapped by Myotismon, he appeared again before Terrence, giving the sword to the Dragon Halfa.
In "The Black Knight" Terrence goes to Avalon once again, only this time with his teammates, in order to seek Kilgharrah's council due to the Dragon Halfa eager to know about the secret of Excalibur.