Boss

Boss (総長 Souchou) was a spirit who appeared early on in the anime adaptation.

Appearance
Boss appeared to be a bald muscular human-shaped ghost with a prominent cleft chin and a black moustache. In the anime he has parts of his motorcycle fused to his back.

Personality
He had a stereotypical thug-like personality and spoke like one as well. He was also fearful of the powerful spirit deeper in Honeido Tunnel that had been ordering him and other lower level spirits around.

History
Boss was the leader of a biker gang. They all died while riding through Honeido Tunnel when the rider at the front slipped on a banana peel and caused an explosive pile-up.

The Most Horrific Haunted Place Omake
Reigen mistook him for a pro wrestler and treated him to an Exorbitant Salt Punch. In the manga, he was exorcised by Mob, while in the anime he went on to rest in peace after Mob destroyed a ghost trapping him and his gang there and showing him an old photo.

Powers & Abilities
Boss was able to utilize pyrokinetic abilities to attack people who entered Honeido Tunnel.
 * Cigarette Burn Poltergeist: Boss puts his index and middle finger together and releases a very powerful blast of pyrokinesis. It was blocked by Mob's barrier to defend Reigen.