Patrick Delaney-Podmore

Sir Patrick Delaney-Podmore is a headless ghost. He is playful and charismatic, and likes to show off in front of other ghosts. He may be related to Order of the Phoenix member Sturgis Podmore.

Death
Little is known about Sir Patrick's life. However, we do know that he was beheaded (probably was executed, murdered or had an accident).

As Head of the Headless Hunt
Sir Patrick is in charge of the Headless Hunt. He doesn't make any exceptions to the rules - a ghost must be completely headless to join. This came as a terrible blow to the ego of Nearly Headless Nick, who was denied entrance to the Headless Hunt because his head is still attached to his body (albeit barely).

Sir Nicholas 500th Deathday Party
Sir Patrick appeared at Sir Nicholas de Mimsy Porpington's 500th Deathday Party in 1992, where he stole much of Sir Nicholas' thunder by cracking jokes and making light of the somber atmosphere.

The Battle of Hogwarts
The Headless Hunt fought in the Battle of Hogwarts. Therefore Sir Patrick most likely defended the school the best as a ghost could.