Jeff (a.k.a. "The Killer") is the major antagonist of Minecraft Story Mode: The Series.
- Mentioned by Valorad before the ending of Episode One, he was a person who wants to rule the universe by himself, so he created the "Kebab Storm" to rule the universe, kill all people that hates him, and all the treasures he desire.
- "My Experiment Number 1: The Perfect Killing Monster"
- —The Killer src
- Troy (Determinant and Indirectly)
- King Villager (Determinant and Indirectly)
- Nicolas (Indirectly)
- Tony (Indirectly)
- Dream Follower
- A Storm was Risen (Mentioned)
- The Long Search (Mentioned)
- Other Dimensional Expedition (Mentioned)
- The Kebab Storm's Demise (Mentioned)
- What Mysteries Beneath (Mentioned)
- The Zombie Invasion
- The Searching of the Past
- Chance of a Lifetime
- Endless Dreams
- He is strongly referred to "Jeff the Killer".
- He summoned the Undead Wither in the Nether before he summoned the Kebab Storm.