Entity303 is the overarching antagonist of the Gameknight999 series, appearing as the main antagonist of the Mystery of Entity303 series. He is a former Mojang employee who was fired for creating the Herobrine virus. He has stolen Gameknight's father's digitizer to go into Minecraft and wreak havoc in the game.
Terrors of the Forest
Entity303 creates a time portal to the Great Zombie Invasion to kidnap Crafter's great-uncle Weaver. Without Weaver in the timeline, there is no one to teach Crafter his love of TNT that helped them through all their battles with monsters.
Entity303 takes Weaver to the present day, where he had added the Twilight Forest mod to Minecraft. On seeing him, Gameknight follows him through the Twilight Forest mod. Entity303 tries to lure Gameknight toward the glacier where the Snow Queen resides, as a cover for him taking Weaver to the White Castle, but Gameknight sees through his plans. Gameknight and his friends battle the Naga, the Lich King, and the Hydra in the process.
At the White Castle, Entity303 creates an enchanted book that will take him into the Mystcraft Ages. A manticore keeps Gameknight and his friends busy while Entity303 escapes into Mystcraft.
Monsters In The Mist
While in Mystcraft, Entity303 forms an alliance with King Iago to create a rocket to take him out into space. King Iago and his servants try to repel Gameknight and his friends, only to be overpowered. During the final battle, Entity303 gets into the rocket and blasts off into space.
Mission To The Moon
Entity303 flies across space, heading for the edge of the universe. He reaches the end and prepares to unravel the universe, only for Gameknight and his friends to reach him. Entity303 is shot with Forpech's staff, causing him to see the error of his ways. Entity303 helps Gameknight fix the damage, then guides him to the time portal where he took Weaver from. Gameknight returns Weaver to his own time period, repairing the timeline.
- The Gameknight999 incarnation of Entity 303 is based off of the titular main antagonist of the infamous Minecraft Creepypasta of the same name created by thespeed179.
- Entity303 may possible be based on Herobrine.
- Entity303 is the fourth User-That-Is-Not-A-User, after Gameknight999, Monet113, and Monkeypants271.
Minecraft: Story Mode