The Jakbow was the weapon of choice used by Rexacor who lived deep inside the Earth's CoreWorld. In it's normal configuration, it fired stunbolts. However, these bolts were ineffective against the stone Golem Soldiers.
The weapon was 'souped up' by Tracy the Gorilla, making it the most powerful Jakbow in existence, according to Jake Kong Jr.. Now it was able to turn the Golem back into their boulder form with a single hit.
The Jakbow was first used in the episode Inside Out.