Iago is the (former) secondary antagonist of the Aladdin franchise. He is Jafar's former pet parrot.
In the first movie, he was always on Jafar's side, giving him evil ideas and doing his evil bidding. He steals Aladdin's lamp and gives it to Jafar. When Jafar turns into a genie and gets sucked in his lamp, he drags Iago with him. In The Return of Jafar he had a much bigger role than the first movie. He escapes Jafar's lamp and saves Aladdin's life, which wins Aladdin's trust. But when a thief named Abis Mal releases Jafar from his lamp, he threatens Iago to lead Aladdin and his friends into a trap. When it works, Iago feels bad for betraying his new friends and sets them free. In the final climax, Iago saves the day by kicking Jafar's lamp into lava, destroying Jafar and winning Aladdin and his friends' trust