Oh, you can get shadows anywhere. In fact, Shadow will be more powerful underwater, because it's darker. But anyway.
"Thank you. First: yes I'm made of blackness, yes I have glowing red eyes, yes my fingers look like claws and no, I'm not evil; I just happen to be the anthropomorphic personification of shadows so I kind of have to look like this. Now that we've got that out of the way, I'm Shadow."