Nab Lasaro is one of the many mages of Fairy Tail.
Not much is known about Nab Lasaro, except that he seems to hang around the Request Board often, even though he doesn't get much jobs or missions to do. He shouts at Natsu when he breaks the Mission board, knowing Natsu Dragneel was going to do something bad. He also says he prefers solo missions when Lucy asked him to go on a mission with her.
(Source: Fairy Tail Wikia)