Ja-Kal is the leader of the mummies who protect Presley Carnovan.
In ancient Egypt, Ja-Kal was a hunter who had a wife Tia and a baby son named Padjet. Ja-Kal also had a brother Arakh and a nephew Kimas. When he left to battle Scarab for the life of the prince, Arakh helped Scarab defeat them. While his brother was also defeated that day, Ja-Kal died without knowing what happened to his wife and child.
Realizing the threat posed by the mummies wise leader, Scarab once used a ceramic falcon idol to attack Ja-Kal's animal sign. Scarab's plan started to work when Ja-Kal thought he was doing something wrong and the others fought for leadership. When Scarab captured Ja-Kal he placed a tracking device on him, allowing Ja-Kal to escape so he would lead him to Presley. When Ja-Kal did return to the others at a youth center party, Scarab ambushed Ja-Kal and the others. Scarab tried to use his falcon idol again but Nefer-Tina destroyed it. Freeing Ja-Kal from it's spell and forcing Scarab to retreat.
Ja-Kal once lead the Mummies to Presley's school one night to get the stone obelisk that had once summoned Chontra, in order to prevent it's power from accidentally being abused. Milton Huxley found the obelisk first and activated the device thinking it to be a science project. Mr. Huxley was then transformed into a powerful magical being with a whole new personality, calling himself "Milton the Magnificent". While Mr. Huxley stole, did property damage and caused mischief. Ja-Kal tried to help the man but was accidentally transformed by the obelisk and became "Jerky the Great". "Jeky" and "Milton" went for a joy ride taking Presley with them. Presley tried to reason with Ja-Kal his words at first appeared to get through, but the "Jerky" personality was to strong for Ja-Kal to overcome. Soon "Jerky" and "Milton" battled on the runaway cable car over the obelisk. Eventually Ja-Kal was returned to normal and the obelisk was lost in the ocean.
Once while battling a Chinese fire-breathing dragon summoned by Bes. Bes became angry and swapped the minds Ja-Kal with Nefer-Tina. Bes continued swapping peoples minds until Presley stole his magical coin and destroyed it. Putting Ja-Kal, and the others back in there proper bodies.
When a new exhibit was about to be featured at the museum. Two mummy cases were included, and Ja-Kal noticed that one was labeled "Kimas" and the other "Scorpion". Worried that one of the caskets contained his brother, Ja-Kal went to the museum later that night to investigate, where Set and Anubis attacked him. They then stole the sarcophagi for Scarab and escaped before Ja-Kal could catch them.
Later Ja-Kal and a revived Arakh confronted each other at the museum. The battle ended in a draw and Scarab revived Kimas to fight his uncle. Instead of attacking his uncle, Kimas greeted Ja-Kal warmly, for his part Ja-Kal was extremely cautious and was hesitant to take Kimas to the mummies hideout. Kimas became angry at Ja-Kal for treating him like an enemy and went back to Scarab and his father. As Ja-Kal contemplated Kimas and his trustworthiness. He learned that if Arakh's scorpion charm were destroyed, Arakh's scorpion armor would be sent back through the Western Gate forever, taking Arakh with it. Kimas then led Ja-Kal into a trap at Fort Point, but discovered Ja-Kal had never betrayed him. Kimas then defended Ja-Kal from Arakh and destroyed the charm sending himself and Arakh back through the Western Gate and saving Ja-Kal.
Ja-Kal doesn't have very good people skills. He's often too uptight and serious. This is only because he doesn't wish to fail in his mission. To him, the harder you work, a better person you become.
Ja-Kal worries the most for Presley's safety, often acting as a father-figure to him. He commonly uses hunting terms to talk to others and explain situations. Ja-Kal commonly cares for others needs first and his own second.
- It's not entirely certain who is Ja-Kal's patron spirit, and creator of his armor. There is much evidence to suggest that it is Ra. Ra was often depicted as the sun itself as well as it's protector in ancient Egypt. The fact that Ja-Kal's armor first manifests as a bird made of flames could be a nod to this.
- Horus the falcon-headed god of the Sky, war and protection may be Ja-Kal's patron god do to the fact that Ja-Kal calls upon Ra as the other mummies do when they call there armor. A possible indicator that while Ra may have brought the four deity's (Bastet among them) together in a common goal, Ja-Kal's armor was actually forged by Horus himself.