The Mummy was once an unnamed pharaoh in Ancient Egypt, who was also a powerful sorcerer. At the time of his death, his tomb was placed under a curse that would raise him again as an undead, if ever a mortal should venture into his resting place.
One day, thousands of years into the future, exiled time master student Savanti Romero decided to take revenge on his former teacher by turning all mankind into monsters. To accomplish this, Savanti wanted to recruit a number of powerful creatures of the night, including the Mummy. To undo the invasion, his nemesis Renet met with her friends, the Ninja Turtles, and took them back to the past to intercept Savanto and prevent his recruitment mission in the first place. However, by invading Pharaoh's grave, they activated the curse, thereby bringing his Mummy back to life and drawing his wrath, so that Savanti could all too easily persuade him to join in his plan.
The Curse of Savanti Romero: When the Turtles and Renet traveled to the Pharaoh's tomb, they disturbed his resting place, thus awakening him. He then joined Savanti Romero in his battle against the Turtles. When Renet failed to send Savanti back to his prehistoric prison, the Pharaoh joined Savanti when he traveled to Transylvania.
The Crypt of Dracula: In Transylvania, the Pharaoh joined Savanti when he traveled to Dracula's Castle. Later, when the Turtles, Esmeralda, and Vulko fought Savanti and his forces, the Pharaoh helped defeat the turtles and he also turned Vulko back into a werewolf. He then joined Savanti, Count Dracula, a werewolf Vulko, and a vampire Raphael in their time-travel to Germany.
The Frankenstein Experiment: As part of his recruitment mission, Savanti made frequent use of the Mummy's magic powers, which proved to be a major asset in the fight against the Turtles and Renet.
Monsters Among Us!: When Count Dracula, one of Savanti's allies, turned on his master and took the Time Scepter, Savanti incited the Mummy on him. Dracula, however, was able to effortlessly turn the Mummy into a pile of dust with his own powers.