The Hellhound is a fictional demon in the prime reality of the Marvel universe of Marvel Comics. It was created in 1992 by Chris Cooper, first appearing in issue #2 of the 1st volume of Darkhold: Pages from the Book of Sins.
Background[]
Hellhounds are summoned by the Darkhold. It tracks down what you summoned it to find and once that's done it gets at the page which summoned it so it can go back home. The Hellhound won't stop until it does. The Hellhound is the size of a large pig with teeth the size of daggers, possesses superhuman strength and speed, and is incredibly tough, being able to survive being hit repeatedly by laser defenses.