Ant-Man - can be found north of the diamond staff icon on the map.
Beast - unlocked after completing story level 8 (Juggernauts and Crosses).
Beetle - can be found east of Central Park.
Black Cat - use the code P9OWL0 or can be found near the Taking Liberties mission icon on the map.
Black Panther - unlocked after completing his three events in the Manhattan Hub
Black Widow - unlocked after completing story level 1 (Sand Central Station).
Doctor Octopus - unlocked after completing story level 2 (Times Square Off).
Doctor Octopus Ultimate - can be found in the bonus level Tabloid Tidy Up during free play.
Howard The Duck - use the code J58RSS or unlocked after completing the bonus level Nuff Said.
Phoenix - unlocked after completing the bonus level Put Up Your Dukes.
Rhino - unlocked after completing story level 12 (Rapturous Rise).
Rocket Raccoon - unlocked after completing his three events in the Manhattan Hub.
Sabretooth - unlocked after completing story level 4 (Rock Up at the Lock Up).
Spider Man - unlocked after completing story level 1 (Sand Central Station).
Spider Man F.F. - unlocked after completing the first Ghost Rider event.
Spider Woman - can be found in the southern part of Manhattan.
Squirrel Girl - can be found on the docks northwest from the Put Up Your Dukes mission icon on the map.
Toad - unlocked after completing his three events in the Manhattan Hub.
Viper - can be found along the road that runs through Central Park.
Vulture - unlocked after completing the bonus level Nuff Said.
Wasp - can be found near the Oscorp Building.
Wolverine - unlocked after completing story level 4 (Rock Up at the Lock Up).
Wolverine (Cowl) - use the code OAW2LB or can be found in the bonus level Put Up Your Dukes during free play.