"She puts her tongue a little in her heart/ and chides without thinking" II.i.106-107. Iago is most definitely the antagonist. How he manipulates everyone around him, and how he acts towards women shows that. He's that kind of guy that when you're with him, he doesn't seem to bad. However, as soon as you realize that he's on every one's side, but in the end is really on his own team, you realize that he's a bad guy. But, to me at least, Othello doesn't seem like the protagonist. If anything, he'll be a sort of antihero in the end, and of course, die. I think that Cassio may end up being the real protagonist.