Jackborg(known as HyJack later on) is a character in Elmo’s Country 4 and 5. He briefly made his debut in the former.
Jackborg was activated at the end of the fourth film, complete with Jack’s memories. Jack uses Jackborg as a substitute body, but doesn’t need it, as he is going to the Realm of the Deactivated for that reason. Later, Zoe and Clono-Oscar take control of it, and use it to fight Jack and Elmo after they are resurrected. However, Oscar, who is revealed to have been freed from Anti-Elmo’s control, stops HyJack. Before HyJack can attack them again, the real Jack destroys it, releasing Zoe’s memories.
Jackborg is a robot designed to look like a human, similar to Terminator. For unknown reasons, he has green blood. When Zoe takes control of it, it begins to suffer damage from Elmo, even losing an eyeball. It has a metal skeleton and glowing red irises underneath its eyes.
Because he is a replica of Jack, he acted exactly like Jack. But after Zoe and Clono-Oscar take control of his body, he acts exactly like Hybrid(or Zoe).
Jackborg is shown to possess a copy of Jack’s machete, and has good fighting skills; however, it loses to Elmo. This is most likely because its machete isn’t the original.