black spiderman - complete 20 city events and collect15 tokens
rhino - complete 25 city events and collect 28 tokens
Play as Black Costume Spidey in Mulitplayer:
Reach 100% completion.
Play as Carnage in Multiplayer:
Reach 80% completion.
Black Costume in Single Player:
When any of Spider-Man's missions are loading, hold select to play in the symbiote costume.
This trick only works in Venom is in an area with a ceiling overhead. When he's dying and falling to his knees, quickly drag the stylus from him to the ceiling. He should get up and keep going with an empty life bar.
Thanks to Revolution Readers Clark, Sonn, and Foosie!