Putting a EULA in your user's face is going to put them off. Ask yourself why no other iOS app does this.
At best apps add a hyperlink to their "terms of service" which will open in Safari when tapped, and perhaps a note that if you sign in, you agree. Check out the Game Center account creation process if you want an example on how to design this.
PDF or PNG are terrible ideas, display either a HTML webview or a simple text view.