Blackrosekane89Featured By OwnerJan 15, 2013Professional General Artist
It's kind of like drawing celebrity portraits, or fan art. Technically it is illegal, but as long as you're not selling it, they usually don't mind.
Look at E.L James (the author of 50 shades of grey). 50 shades of grey was originally a fanfic of Bella and Edward (Twilight) when she started selling it she changed the names. Stephenie Meyer could have sued for using her characters for the original fan fic, but opted not to. No telling