Billionaire Industrialist
Or Inhumanly smart scientist
Then there's always: Over-the-top Superhero/Secret Agent...
Wait, that's the one. Dream Job: Superhero....but if I'm Tony Stark, I can be a superhero AND a billionaire industrialist AND an inhumanly smart scientist....Yeah, I take all of those.
Realistically: Billionaire Industrialist or Comic Book Artist/Writer/Creator