Marrow (real name: Grok) is an undead skeleton who was a powerful berserker-class gladiator when he was alive. People feared him then, and they still fear him now. Despite his lack of muscles as a skeleton, his height and bulkiness are enough indicators to warn anyone in his path how strong he really is. He's quick to anger, uneducated, and often acts before thinking, traits that are the reasons for his early death.