Coral

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

Background
Coral was not related to Gern Blanston or his other thralls, although Gern did get Carol and Coral confused and considered them all a make-shift family.

Trivia

 * Gern being a necromancer dancer and wearing a red dance vest is an allusion to the vest Cadence wore in Crypt of the NecroDancer.  It is possible, then, that Coral is a reference to the other playable character, Choral, which may even be the intended spelling of Coral's name.
 * "Coral" is an anagram of "Carol", one of Gern's other undead thralls.