Prune Face's real name was Orrimaarko, and his race Dressellian from the planet Dressel. He was recruited into the Alliance by the Bothans (often mentioned but never seen on screen) to fight subjugation of his homeworld by the Empire. He was on the Endor strike team during the events of ROTJ, and was a bit miffed when Han Solo was picked to lead rather than himself, who he deemed more qualified. No word on how he got the eyepatch though.
Want more? His full Wookieepedia article
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