Mr. Grimm's Gunner in Roadkill.
The Skulls are one of the four factions in Twisted Metal (2012). They are lead by Mr. Grimm, and his fellow gang members also are stuntmen like him. The main bulk of their vehicular forces consists of motorcycles, although they also control a pair of massive monster trucks known as The Brothers Grimm. They are the main enemies of Needles' story.
The Skulls' Gunner
In the true context of his story, Mr. Grimm never actually had a gunner and participated in his side of the tournament completely by himself, as he drove Reaper throughout the tournament. However, Mr. Grimm does have a member from his group assist him should he pilot a two-manned vehicle. This member of The Skulls has a similar appearance to Mr. Grimm, although instead of dreadlocks the gunner sports a mohawk.
Considering Mr. Grimm began and ended the tournament on Reaper, it is speculated that Mr. Grimm, during his story, did not have a gunner assist him.
Traits
The Skulls have a wide array of weapons at their disposal, although the vehicle they use the most is Reaper. When not using their distinctive chopper, they may be seen driving muscle cars such as Death Warrant and Roadkill.
The Skulls seemed to have the smallest gang of all the factions in Twisted Metal (2012). In their boss battle, they only had four members (two in each of the Brothers Grimm). However, the group was bigger before this battle, as they were the bulk of Needles' opposition.
The Brothers Grimm
By the end of the Twisted Metal tournament (from Sweet Tooth's perspective), there were only four members of The Skulls left, including Mr. Grimm. In a final effort to destroy Sweet Tooth and win the tournament, The Skulls brought out the Brothers Grimm: Two massive monster trucks (Hammerhead & Slayer) each piloted by two members of the gang. In a dangerous battle, one of the Brothers Grimm was destroyed, leaving Mr. Grimm and his gunner alone to fight Sweet Tooth and his minion. Despite deploying hidden armor plating, they were unable to overcome the mad clown, and perished when their remaining vehicle exploded.