Gavin MacLeod

Gavin MacLeod was Crowley's son and a ghost.

Background
Gavin was born in Scotland in the late 1600s to Crowley, then known as Fergus Rodrick MacLeod. The two hated each other greatly, and after Crowley died, Gavin came to the US as a captain of a trading ship. His ship later sunk and Gavin drowned and became a ghost. When summoned by Bobby, Gavin immediately thought he was in Hell.

Season 6
Divers found his ring and donated it to the Naval Museum in Andover. His ring was later stolen by Rufus Turner, who attempted to deliver it to Bobby. Due to the police chasing him, Rufus swallowed the ring.

When Sheriff Jody Mills managed to get Rufus out of jail, Rufus gave Bobby the ring. From there, Bobby summoned the spirit of Gavin and they talk. Gavin had no love for his father and told Bobby everything (including how Crowley became a demon). Crowley and Gavin met again when Bobby summoned him. Crowley initially pretended to get emotional, but then quickly admitted that he hates Gavin. He then told Bobby he could torture Gavin all he wanted, but Bobby informed him that Gavin wasn't a hostage. Crowley was shocked when he found out that Gavin told Bobby where Crowley's body was buried. Having gotten his revenge on his father, Gavin vanished.

Season 9
His spirit was agitated by Abaddon and possesses a man and she later uses him as a chip assuming Crowley has some humanity, having been injecting himself with purified human blood. She torturers him for a while clenching him in a telekinetic bind when Crowley finally gives in. He hurtles out the idea of him being 'Prince of Hell' (albeit no powers) where Crowley says some use came of them being related. Dean and Sam say he has to be sent back due to ripple effect that this history alteration will cause, but Crowley teleports him away and tells him how he dies on the boat.

Appearances
Gavin Macleod
 * Season 6
 * Weekend At Bobby's
 * Season 9
 * King of the Damned