He appeared in the Ultimate Spider-Man episode "Halloween Night at the Museum".
Jack O'Lantern is the result of Morgan le Fay magically placing a pumpkin on the head of a security guard in her plans to bring about the end of the world. Jack O'Lantern attacks Spider-Man,Jessie Prescott, and the Ross Kids in the space exhibit. While Spider-Man handles Jack O'Lantern, Jessie and the Ross Kids hide out during the battle. After Morgan le Fay is defeated, Jack O'Lantern regresses back to the security guard.