Jake's full designation is Jungle Automatic Killer - Experimental II. He was designed by the scientists of Project M to aid U.S. military personnel during World War II. When the first G.I. Robot was destroyed saving a crew of marines in the Pacific, the War Department deployed a fighter plane to Tattu island to deposit his replacement, J.A.K.E. II. Sgt. Blaney of Green Patrol found the crate containing J.A.K.E. II's robotic components, and his men worked feverishly to assemble him. At first, J.A.K.E. II failed to activate, and Blaney believed that they had made a mistake in piecing him together. Shortly thereafter, the Japanese soldiers stationed on Tattu Island unleashed their own version of the G.I. Robot - Krakko, the Samurai Robot. Krakko attacked Green Patrol's camp and it appeared that all was lost. Fortunately for Sgt. Blaney's men, J.A.K.E. II activated and rose to their defense. Disconnecting his own head, he wielded it like a flail and used it to utterly destroy the Samurai Robot. Blaney and the rest of Green Patrol were confident now that J.A.K.E. II would be just as valuable to them as his predecessor. 
Soon after, the administrators at Project M united the G.I. Robot with its predecessor's colleague Sgt. Coker. They were stationed briefly on the mysterious Dinosaur Island, which was used as a proving ground for experimental combat exercises. J.A.K.E. II was later assigned as an unofficial member of the covert military detachment dubbed the Creature Commandos. He later acquired a robotic canine companion known as C.A.P.. 
J.A.K.E. II was decommissioned in 1945 after the war had ended, and has remained in a state of dormancy. He is still operational however and may be called upon again for service at some future point in time.
All of the G.I. Robot's powers are functions of its design and programming. As a Robot J.A.K.E. II possesses all of the various superhuman attributes with some improvements over it's predecessor J.A.K.E. I:
- Superhuman Strength: As a Robot J.A.K.E. II is superhumanly strong and possesses beyond the human limit.
- Superhuman Speed: As a Robot J.A.K.E. II can run and move at speeds that are beyond the physical limits of the finest human athlete.
- Superhuman Durability: As a Robot J.A.K.E. II body is composed of metal. This armor plated material makes him durable to most attacks.
- Superhuman Stamina: As a Robot J.A.K.E. II can exert itself well beyond the human limit as long as he has sufficent power.
- Superhuman Agility: As a Robot J.A.K.E. II agility, balance, and bodily coordination are enhanced to levels that are beyond the natural physical limits of the finest human athlete.
- Weapons: His left arms consist of a fully functional machine gun, which can fire both bullets, mini-torpedoes, and small anti-aircraft missiles.
- Flight:He can also fly for short distances thanks to small rockets in his boots.
- Superhuman Intelligence: He also is capable of rapid analysis of huge amounts of data.
- Audio Sensitivity: J.A.K.E. II can adjust the sensitivity of his audio receptors to a point where he can detect the faintest of sounds.
- Visual Scanners: J.A.K.E. II is capable of scanning life forms, energy sources and other objects detecting the substances that they are composed of.
- Vocal Imitation: Unlike his predecessor J.A.K.E. II is capable of replicating and mimicking the voices of other people enabling him to impersonate them and even create his own.
- Telepathic Link: He is able to monitor the other Rooks, who are telepathically linked thanks to an alien DNA infusion derived from Starro the Conqueror. If J.A.K.E. determines the DNA is gaining control, it will terminate the link by killing its team.
- Empathy: The G.I. Robot, while not in any way sentient, has demonstrated the ability to feel human emotions such as courage, a sense of loyalty and even loneliness. Whether the G.I. Robot is experiencing true emotions or whether his programming is simply enabling him to mimic these sensations is a matter of speculation. Sgt. Coker believed that J.A.K.E. II was capable of harboring genuine human feelings.
- Automatic machine gun(s)
- Anti-Aircraft Missiles
- Flame Thrower
- Miniature Torpedos
- Although this character was originally introduced during DC's Earth-One era of publication, their existence following the events of the 1985–86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and should be considered apocryphal.
- 21 Appearances of J.A.K.E. II (New Earth)
- 4 Images featuring J.A.K.E. II (New Earth)
- Quotations by or about J.A.K.E. II (New Earth)
- Character Gallery: J.A.K.E. II (New Earth)