The Stallion of Doom is a fictional animal featured in comic books published by Marvel Comics. It is part of the mainstream Marvel Universe and is associated with the Thor line of comic titles. It first appeared in Thor, Volume 1 #132 in September, 1966.
The Stallion of Doom was a horse of Asgardian lore. It was a black steed associated with the Valkyrie. When a warrior who had proved himself worthy of entering the halls of Valhalla, the Stallion of Doom would appear at the warrior's point of death and ferry him or her into the afterlife.