He is portrayed by Corey Feldman in all three movies.
Edgar and Alan worked in their parents' comic book store at a very early age, not for money, but for survival guides and tactics. They somehow surmised, and were correct, that their hometown Santa Carla was fraught with vampires, so they read a comic called "Vampires Everywhere" to learn how to destroy blood-suckers.
When they were both around twelve or thirteen, the Emerson family moved to their town, and they warned the younger brother Sam about Santa Carla's vampires. This paid off later when Sam's older brother became a half-vampire; Sam asked for help, and the Frogs obliged. The two pairs of brothers set out to destroy a small clan of vampires to turn Sam's brother Michael and Star, Michael's love interest, back into humans. In the vampires' lair, the clan was asleep, suspended from the ceiling when the Frogs and Sam arrived. Edgar managed to kill one by staking it through the heart, but this awakened the other three killers. The Frogs and Sam fled back to the latter's house with Michael and Star. The vampires attempted to kill all of them in the house, but were unsuccessful and killed in gruesome ways. Edgar and Alan managed to kill one of them by making him fall into a bathtub full of holy water, while Sam managed to kill another, and Michael impaled the vampire leader David on a pair of mounted antelope horns.
Sometime between the first and second films, Edgar's brother, Alan, became a vampire by unknown events.
Chris is skeptical at first by Edgar's theory that Nicole and Shane are vampires, but comes around eventually. The two are unable to pin-point a location on Shane's nest to kill him, so Edgar suggests that Chris get close to Shane and earn his trust. This leads to Chris becoming a half-vampire himself, but nonetheless he discovers the location of Shane's lair, a series of old mine tunnels. Edgar kills Shane's clan while Chris himself kills Shane by slicing off his head with a sword after Nicole shoves a stake into his chest.
In Lost Boys: The Tribe, Edgar has moved to Luna Bay and lives alone in a trailer, which he has covered with crosses and garlic to keep vampires away. He also now has a job as a surfboard shaper to pay the bills. He lives in apparent solitude until Chris and Nicole move to Luna Bay as well, the former leaves his address on Edgar's door, hoping to get a job. Later that night, after the siblings go to a party at Shane Power's (who is secretly a head vampire infatuated with Nicole) luxurious mansion and Nicole unwittingly drinks Shane's blood, turning her into a half-vampire, Edgar knocks her out with a surfboard and attempts to kill her, but Chris obviously calls that off.
Edgar is skilled in tracking down vampires and recognizing them. He is self-trained in handling special weaponry that assists him in killing blood-suckers, and is known to even design a few of his own. He always keeps some sort of defense on him, be it balloons full of holy water or custom-made metal stakes.
Edgar is an ordained minister, given him the title of Reverend. This gives him the ability to take any water and bless it with a prayer or incantation, thus turning it into holy water.
Edgar is very dedicated to his "job" of vampire hunting. He is always ready and willing to kill them and always carries around special weaponry to eradicate them. If someone is hesitant to eliminate vampires, he tends to get in their face and express how evil he sees them to be. The only exception to this is his own brother, Alan, who became a vampire when they were either teenagers or young adults. Edgar is always trying to find the head vampire responsible for Alan's transformation, determined to return his dear brother to normal; he achieved this goal in Lost Boys: The Thirst. This shows that he has a tough, but somewhat warm disposition. He is rather paranoid and mistrusting of people he is not familiar with due to his years of hunting vampires that can hide their monstrous features to appear as normal.