Endeavor Group Holdings Inc. , the Los Angeles-based entertainment powerhouse and owner of the William Morris Agency, sports and modeling agency IMG and mixed-martial-arts outfit UFC, is making a second attempt to go public after filing paperwork with the Securities and Exchange Commission on Wednesday. Tesla Inc. Chief Executive Elon Musk is joining the board ahead of the deal, said the documents, which also disclosed that it intends to use the proceeds along with its own equity to acquire the 49.9% stake in UFC that it doesn't already own.