- “I love the way your foul little mind works!”
- ―Jafar to Iago
Before the Isle of the Lost
In the first film, Iago has a supporting role as Jafar's sidekick, and also served as his spy, disguising himself as Jafar's mindless pet parrot.
Iago is first seen during his and Jafar's confidential visit to the desert, in the middle of the night, where they are met by a thief, Gazeem. After forcefully handing over a stolen piece of a golden scarab, courtesy of Iago, Jafar is able to create one full, magical scarab, which reveals the location of the Cave of Wonders. Gazeem is ordered to enter in order to steal a magic lamp (as Jafar wishes to use the Genie to take control of Agrabah) but is killed in the process, as a result of being unworthy to enter. A frustrated Iago voices his annoyance, believing their mission to retrieve the lamp will forever be an impossible task to complete. Jafar, however, remains level-headed and assures Iago that the lamp will be in their possession once they find the "Diamond in the Rough" that the cave's tiger head guardian spoke of.
After returning to Agrabah, Jafar and Iago visit the Sultan, needing his diamond ring to uncover the individual worthy to enter the cave. Here, Iago shows his disdain for the Sultan; specifically due to the ruler constantly shoving "moldy, disgusting crackers" down his throat. Jafar reassures Iago that they will no longer have to abide by the Sultan's reign in good time, with Iago gleefully plotting to exact revenge once that time has arrived.
After discovering a boy named Aladdin is the one worthy enough to enter the cave, he travels to the Cave of Wonders with Jafar, though the mission goes awry, resulting in both the lamp and Aladdin, being lost. Afterward, at the palace, Iago concocts a new plan involving a rise to power. He advises Jafar to marry Jasmine, which would result in the vizier legally becoming the sultan. Once he holds such power, Iago continues, they'll kill Jasmine and her father. Jafar agrees, but their plot is interrupted by a new coming prince: Ali Ababwa. Jafar and Iago soon discover that Ali is Aladdin, and holds ownership over the lamp. Iago is sent to retrieve it, doing so by cunningly disguising his voice as Jasmine to lure Aladdin away from the lamp.
With the lamp in his possession, Jafar takes over the kingdom, bestowing Iago with his own turban, to signify his leadership, as well as his own lounge area near the throne, with a throw pillow and plenty of fruit for his pleasure. After scarfing crackers down the dethroned Sultan's throat, Iago wallows in luxury before noticing Aladdin trying to steal back the lamp. Abu, Aladdin's monkey, tackles Iago to prevent him from alarming Jafar, which leads to a tussle. As a battle ensues between Jafar and Aladdin, Iago watches sadistically, rooting for Jafar to eliminate the threat, until Jafar wishes to become an all-powerful genie. Unfortunately for Jafar, this means an eternity of slavery and imprisonment, though his greed and lust for power made him oblivious to this.
As Jafar is quickly sucked into his lamp, Iago tries to flee, only to be grabbed by the villain, and dragged into the lamp, as well. Trapped and annoyed, Iago berates Jafar on his foolish decision including arguing about space, just as the two villains are sent to the Cave of Wonders to endure 10,000 years of imprisonment.
- Iago was originally meant to be a snobbish parrot with a British accent. However, to further the comedy, his character was changed drastically to what animator Will Finn calls "Gilbert Gottfried as a parrot".
- Iago was originally going to be voiced by Danny Devito
- Years later, he would go on to voice Philoctetes in the Disney film Hercules
- According to actor Jonathan Freeman (Jafar), the original idea was that Iago would sound like Jafar, meaning that Jonathan would have to play the two characters. However, the people at Disney changed their minds.
- Although, this was referenced in Aladdin when Iago did an impression of Jafar with Jonathan Freeman voicing Iago's impression of Jafar.
- In the book, Isle of the Lost: A Descendants Novel, it's somehow revealed that Iago has lost his speech ability since he now talks like a regular parrot.
- While in service to Jafar, Iago proved to be one of the more competent henchmen: he successfully retrieved the lamp for Jafar after easily tricking Aladdin by mimicking Jasmine's voice; he came up with a number of excellent schemes for Jafar to seize power; and despite his comedic demeanor, he did not display (at least in the first film) any signs of genuine stupidity, despite getting injured from time to time, and he can also be rather sadistic, as he suggested murdering the Sultan and Jasmine in the event that Jafar would manage to marry her, namely "drop them off a cliff."