Late comedian Gilbert Gottfried will forever be identified as the voice of Iago, but his casting actually helped reshape Aladdin. Gottfried was generally regarded as a comedian's comedian, someone who commanded respect within his field, even if his stage persona naturally made him seem silly. The most notable feature of Gottfried's act was his uniquely harsh voice, one not at all like his normal speaking voice, so it makes sense that the role he's most synonymous with is strictly a vocal performance.
Depending on who one were to ask, the early 1990s golden age of Disney animation was its best period ever, and usually battling The Lion King for the top spot is Aladdin. While Robin Williams' bombastic performance as Genie rightly tends to get the lion's share of love for Aladdin's characters, Gottfried's Iago is often the runner-up in that regard. Gottfried's always annoyed, sarcastic sidekick fits perfectly with villain Jafar, a man villainously full of himself.
Gottfried fits Iago so well in fact that many might be inclined to assume the role was originally written with him in mind, but that's not true, at least not completely. The roles of Iago and Jafar were actually first intended to be reversed, with Jafar a more outwardly comedic character, and Iago being his straight man sidekick with a distinguished British accent. During development, the idea was hit upon to make Iago the comic foil of the two, but it wasn't until Aladdin's makers saw Gottfried's small but hysterical role in Beverly Hills Cop 2 that the pieces came together on how to do that. Gottfried was cast, and the Iago role was redesigned to fit his style.
While the word iconic gets thrown around a bit nowadays, many would consider Gilbert Gottfried's Iago to be an iconic character in the Disney pantheon. Gottfried remained a constant presence in the Aladdin franchise too, having voiced Iago in both of Aladdin's sequel movies, the Aladdin animated TV series, and even the Kingdom Hearts video games. Alan Tudyk taking over the Iago role in the 2019 live-action remake of Aladdin was the first time the opinionated parrot hadn't been voiced by Gottfried since 1992, illustrating his connection to the part.
It's telling that after earning the hearts of Disney devotees as Iago, Gottfried never struggled for voice acting work afterward, with the comedian having publicly acknowledged that his success with Aladdin opened the floodgates on offers. The fact that a lifetime of voice work traces back to Gottfried's one-scene role as foul-mouthed accountant Sidney Bernstein in Beverly Hills Cop 2 is truly remarkable. Perhaps most ironic of all though is how Gilbert Gottfried, an actor and comedian famous for his willingness to indulge in politically incorrect humor, will forever be best-known for a family-friendly Disney movie.