Greinfarr is a non-player character in Final Fantasy XIV. Originally he appeared during Ul'dah's main story and during the gladiator questline in the original Final Fantasy XIV. In A Realm Reborn Greinfarr does one briefly during the blacksmith questline and later returns to the Stormblood expansion during the alchemist questline.
Final Fantasy XIV legacy
Greinfarr is close friends with Niellefresne and son of the owner of coliseum. Greinfarr was one of Niellefresne's companions during the parade in an attempt to make him and his companions look like heroes to the townspeople, but the situation gets out of hand and ends up mortally wounding a man named Warburton. Later during a game the Niellefresne's plan is unmasked by Thancred. Corguevais reveals the truth about the plan to Ascilia, Warburton's daughter, and tries to take the girl back to Ala Mhigo. Niellefresne's group intercepts the flight of Corguevais who flees after calling a horde of coblyns leaving Ascilia behind. While Popokkuli and Seserukka try to chase Corguevais, Greinfarr remains to defend the group. Niellefresne's group discovers that Warburton had important information for Ul'dah's future, so Niellefresne tries to resort to necromancy to revive him but ends up murdered by a mysterious figure. 
In his glory days, Greinfarr emerged victorious against J'moldva, the Hellfire Phoenix, during the final of a tournament. During the battle the audience got out of control and J'moldva was seriously injured. J'moldva was considered a traitor to her people. With no choices Greinfarr carries her to Gridania in search of treatment, where she finds a new life.
An anonymous customer orders a gift sword for Greinfarr at Naldiq & Vymelli's. Faezahr summons Greinfarr to collect the weapon personally. Greinfarr is initially intrigued by the gesture, but upon receiving an enigmatic message, he identifies his client as Hellfire Phoenix, who he thought died in Calamity years ago. He accepts the sword, proclaiming that one day he will be at the top of the Coliseum and do justice, and leaves without meeting J'moldva.
Greinfar is a Hellsguard Roegadyn with red skin characteristic of his tribe as well as off-white hair. He has darker patches of skin around his eyes, very dark and muted red but still red. He wears a yellow over-tunic of some kind decorated with reddish brown leather, over a chainmail. He also wears gauntlets of the same red leather and steel guards over his arms, and boots of similar design with chainlinks, red leather and steel guards over his knees.
During the instance in Calamity Cometh quest in version 1.0, Greinfarr is an ally npc assisting the adventurer to defend Niellefresne's group from a coblyns horde.