The Gunners' new defender is an international team-mate of Ozil, and says the pair spoke about the club while at Euro 2016 with Germany.
“We were at the European Championship and we had time to speak," Mustafi told Arsenal Player. “He told me about the club, about the team, and the things that he told me made me come here.
“I noticed that it's a club where I can develop, where I can grow as a player.
“He said that he's happy here, that the people are crazy for football and that it's a team that enjoys playing football the way that he does, the way that I do."