Marvel Ultimate Alliance playable character teaser pack?

On my Xbox 360 I am downloading the playable character teaser pack for Marvel Ultimate Alliance with Xbox Live. I was just wondering what characters it has. Because it says that if you got the Marvel Ultimate Alliance from May 2007 then you don't need to download it because it already comes with those characters. I am not sure if I have that one so I just wanted to know what characters come with the playable character teaser pack. Please help quickly! It is almost done downloading!!! Thank you for all of your answers!