Percival Phyonduul is a descendant of a group of Maltusians who had left their homeworld of Maltus countless years ago in a search for new worlds. During their journey, they discovered and eventually settled on the planet Earth where they became incorporated into human legend as being thought of as one of the fabled Leprechauns of Ireland. Over the many years of living on that world, the Maltusian Leprechauns had forgotton of their ancestry and were unaware of the fact that they had journeyed from distant Maltus and colonized other worlds such as Earth. Thus, Percival grew up, completely oblivious to his heritage and the fact that he was an alien from the stars.
He was eventually discovered by the Guardian of the Universe Ganthet and the Green-Lantern Hal Jordan. Ganthet offered this cousin species of the Oans the chance to reclaim their birthright as Guardians of the Universe but the Leprechauns expressed only disinterest. Much to Ganthet's dismay, it was only the elder Percival who decided to accept this offer and the he was equipped with Oan devices that were tasked with helping him to better access his abilities as well as mentoring him in their proper use. Furthermore, he was given a Green-Lantern Power-Ring until the time he could harness the Glow by himself. Thus, began Percival's training and within a week - the Leprechaun grew not only younger but much stronger.