Fatty Arbuckle

Fatty Arbuckle, often simply called "Fatty", was a humanoid male. At some point after his death, he was animated by the necromantic powers of Gern Blanston, serving with his fellow thralls Carol, Coral, and Stimpy. As a companion NPC, was played by Matthew Mercer, but he followed the instructions of Gern's player, Chris Hardwick.

Background
Fatty was not related to Gern Blanston or his other thralls, although Gern considered them all a make-shift family.

Encounter with Vox Machina
While investigating the ruins of Pyrah after Thordak's escape from the Elemental Plane of Fire, Vox Machina spotted a group of four undead creatures. After killing Carol, the group spotted a blue-skinned humanoid running toward them. He introduced himself as Gern Blanston, then introduced his three remaining thralls:  Coral, Fatty Arbuckle, and Stimpy.

Fatty helped Gern and Vox Machina in their fight with the salamanders and elementals around Cindergrove, who were guarding the area around a portal to the Elemental Plane of Fire. Fatty started the fight by triggering an Ice Storm candle, then served as a beating dummy for the enemies. Although he survived the Ice Storm and several attacks, Fatty was eventually destroyed by Gern as collateral damage when attacking the enemies with a Cone of Cold.

Trivia

 * The name "Fatty Arbuckle" was the stage name of a lesser-known and somewhat-infamous comic actor from the early silent movie era, named Roscoe Arbuckle.  He was a contemporary of Charlie Chaplin.