Predator first appeared as someone who was fucking up Ferris Aircraft after Daddy Ferris came back and took it back from Carol. Steve Englehart (who’s GLs and JLAs are the best runs EVER) came onto the book and it turns out that no-one…across two or three writers…had any idea who Predator was (he was clearly a cast member and someone close to the main characters), what his/her motives were, etc.
Just before Englehart took over (I think), the Predator grabbed Carol and gave her a tonsil-exploring smooch. Englehart took over and made Carol nasty…again (to quote Englehart from the letter column, “That woman is to mood-swings what Eddie Murphy is to comedy”) She did stuff like give Hal an ultimatum: “Give up the ring or give up me. Last chance–blow it and we’re done for good”. She “hostile takeover’d” Ferris Aircraft and threw daddy under the bus, etc. Hal quits the Corps for her and the Guardians say “Ok. :rolleyes: This is like the fourth time you’ve quit in 125 issues. If you quit again, no takebacks.”
Hal says “Up yours, you little blue turds” and is dumped back on Earth, powerless. John Steward is made the new Green Lantern of Earth and Katma Tui is sent to train him.
Hal tells Carol “Hey babe, I’m all yours! I quit the Corps” and Carol says “Eew. You’re just a kinda skeevy pilot–it was your power as GL I was interested in after all. Consider yourself dumped. Toodles.” and she becomes Star Sapphire again (remember, pre-Crisis, the Zamoran’s thing was to search the universe for a chick who looked just like Carol and make her their queen. Up 'till now, she fought the Sapphire and rejected queendom. This time, she happily accepts.
Turns out that
A) Hal dumped Carol during a storyline (a bad one) about 40 issues before. The Guardians had said “You’re spending too much time on your home planet and so we’re banishing you from earth for a year.”
B) This really pissed Carol off and made her pretty unhappy. The Zamorans, Engelhart retconned (he’s the single best Retconner ever–the whole “Manhunters were proto-Green Lanterns” thing? An earlier retcon of Englehart’s from his JLA run) showed back up and offered Carol the job of Queen again right after Hal took off. She refused but used their magic pipe organ (seen in the original appearance of Star Sapphire and never again–like GL 16, circa 1963) and the Sapphire to split her “aggressive male self” off 'cause it was making her so unhappy.
C) This “male self” became the Predator and 1) Set out to fuck up Daddy Ferris (who was a dick from his first appearance) 2) Get even with Hal for dumping Carol for the Guardians and 3) Just generally mess with people who pissed Carol off. Meanwhile, Carol became a helpless little muffin who sat home knitting sweaters and baking cookies waiting for Hal to return (this happened in the pre-Englehart issues. The “her gumption became The Predator” thing was a killer good retcon)
D) The tonsil-kiss was to transfer her gumption back. Hence the ultimatium to Hal followed by the dumping.
She merges back with the Predator and flies off with the Zamorans leaving Hal powerless, ringless, and alone.
Then the Crisis on Infinite Earths happened. The Guardians split into two factions–the wimp/fatalistic Guardians who say “This mess is all our fault. We shouldn’t fight it” and a second batch (who’ll eventually evolve themselves into the Controllers from Legion) who say “Screw that noise. No evil shall escape our sight.” They decide to get their OWN Green Lantern–and after some brain-surgery (so he can’t feel any self-doubt-they’d had enough of Hal’s endless whining about going off to find America and crap) they revive Guy Gardener from a coma he’d been in for 100 or so issues.
The end result of all this after the Crisis ended was that Hal got his ring back and the wimp-faction of the Guardians kinda won. Sorta. Turns out (again, Englehart invented this–this wasn’t part of the story before even though it’s canon now) that Zamorans were the female Guardians. Reunited, they dumped Carol saying “The ‘you’re our queen now’ game isn’t fun any more. There are boys!” and hooked up with the Guardians and they all left the universe (until Millenium–of which, the less said, the better)
So–really, that was it for the Predator. (The run is roughly GL (1960-version) 188 or so (shows John on the cover, beaming his mask off his face) through GL 201. Seriously, if you’re a GL fan, I can’t recommend it enough.