The man who has gone viral online after dressing as Batman’s nemesis, The Joker, during this year’s running of the bulls at Spain’s San Fermín festival has been identified by multiple Spanish media outlets as Chicago man Lacey Mrzena.Mrzena has become one of the most talked-about figures at this year’s multiday event in Pamplona, northern Spain, with his green hair, Joker makeup and multiple clashes with authorities.On Saturday, during the festival’s fifth bull run, police reportedly stopped Mrzena for allegedly taking photos of himself with a cellphone and touching one of the bulls while on the course, both of which are prohibited under San Fermín rules.Revelers run alongside Jose Escolar's fighting bulls during the fifth running of the bulls at the San Fermín festival in Pamplona, Spain, on Saturday.via Associated PressMrzena, described by Spanish media as extremely active on social media, was reportedly issued a fine.Penalties for breaking the rules range from 601 to 6,000 euros (about $700 to $7,000), although authorities have not disclosed the amount of his fine. He did not immediately respond to HuffPost’s request for comment.Mrzena returned to the course on Sunday, without the Joker makeup but still sporting green hair.Video shared by the Diario de Navarra newspaper showed him warming up before the run, only to be intercepted by police and removed from the course before it began.According to Spanish media, authorities prevented him from taking part on Monday as well.