Cyclops, Scott summers, from X-Men. If you don't want to waste money, just put a visor over your eyes and don't worry about the X-Men costume. In public, sometimes he just wore dark sunglasses and regular clothes.
Anyone can dress up as a superhero. Costumes are available at: http://www.costumecraze.com/Superheroes.html and http://www.officialsuperherocostumes.com.
Kinds of dress up games for boys include superhero games. If one is looking for dress up games online, sites one could visit include Dress Up Games or Dress Up Mix.
He dresses up as Scuba Steve.
The Flash
It depends on the event, but Superman is an easy choice. You could conceivably be any superhero.
The superhero superman is who I think says up up and away but I am not positive
Superhero. Masquerade. Animals.
Superhero?; might not be the CORRECT term, but he does look up to Nena. She might not be a "superhero" but to him 'he' is her idol.
The easiest place to find such an item online would be looking through one of the major online stores. Sites such as Amazon have a Princess Dress Up Trunk in stock ready to be shipped.
Because You Could Get Killed. But Over The Years People On The Internet Have Been Posting Videos On You Tube About People Who Dress Up And Get Into Brawls With Gangstas On The Street.
This would be easiest when he's asleep.
If you want to do a superhero comic, invent a superhero, and think up a story for his origin.