Dean: You're back?
Crowley: I'm invested. [Hellhound growls] Stay!Crowley: Not that one. [pats his Hellhound which appears to be about 5 feet high] I brought my own. Mine's bigger. Sick 'em boy!
Dean: You can control them?!
– Crowley and Dean, 5.20 The Devil You Know
When demons send Hellhounds after the demon Brady in 5.20 The Devil You Know, Crowley appears with his own hellhound, which fights the other hounds while Sam, Dean, Crowley and Brady make their escape.
Crowley later summons the hound when Bobby has trapped the demon in a devil's trap in an attempt break the deal for Bobby's soul in 6.04 Weekend at Bobby's. When the hound appears Crowley offers his own deal: "Ten years of living, or ten years as Alpo."