Sci-fi author Charles Bently learns after writing his newest story that the exact way he wrote it ended up happening in real life, including the sea serpent attacking a nuclear submarine. After writing another story, this one about a 2-headed flying monster, which also comes true, Charles is puzzled.

Intent on making deadline, he writes another story, this one about a shape-changing creature called X. He is horrified when X comes after him. At the last minute, he realizes that it was the typewriter that was causing his writings to come to life, and when he threw it from his window, X disappeared as the machine hit the ground.

X, or rather a larger monster resembling him, was among the monsters summoned by the Mole Man to greet Adam Warlock upon his arrival on Monster Island.

When the demon called Nightmare invaded the dreams of a young Peter Parker (the future Spider-Man), he used several monsters to attack Parker, including X.