Imu is a Parrot (convincing evidence)
This theory is one of the most compelling theories I've ever seen, so I've decided to compile all of the strongest clues so far
1. Obvious Physical Resemblance with a Parrot
During a Q&A session, a reader asked "Could Imu-sama's true identity perhaps be someone whose lips are extremely pointy?"
Oda replied with "Yeah. I'll leave this on 'read' and ignore it"
Also, the long dress that Imu wears could also be explained since parrots are known to have long tail feathers
The one below is probably the most compelling visual clue I've seen, if you look around his neck, you can see parts that look like feathers
2. Stereotypical Pirate with a Parrot (Joyboy & Imu)
A common stereotype, or rather a key theme, is that a pirate has a pet Parrot on his side
This could be seen as Imu, a parrot, on the shoulder of Joyboy.
3. Imu's Room Resemblance of a Bird Cage
Birdcage is one of Doflamingo's signature ability.
Speaking of Doflamingo, Doflamingo is a subtle shadowing/preview to the end game between Nika and Imu.
Doflangmino would be Imu, the birdcage is the red line, the false history of king riku would be the fabricated history by the world government, the way Doflamingo controls people with srings could be a metaphor for how Imu controls the whole world, and Luffy's liberation from Doflamingo could mean that Nika would eventually be liberated in the end
4. Ties with Shakespeare's play Othello & Disney Aladdin
Probably one of the most interesting theory
Imu's Ability "Dominion Reverse" is inspired from the boardgame Othello.
Othello is also a famous Shakespeare's Play. The main antagonist from the play Othello is Iago.
In Disney's Aladdin, the main villain Jafar has a parrot named Iago, same name. This would've been a weak case if it wasn't for Luffy to now has a Genie form
5. Scene of Imu with a Strawhat
There was a theory that the strawhat was huge, but if Imu is a small parrot, this illustration of a relatively large strawhat would make perfect sense
6. Nefertari D. Lililth
There is a flower called Impatiens psittacina, this flower also has common names such as Princess Lily, Parrot Flower.
In the room of "flowers", we can see a portrait of Lily, who resembles Vivi
Imu was likely Lily's Parrot, which could explain his odd speech pattern where he says "Imu Wa" in third-person, he might be trying to imitate how Lily talked to him.
7. Recurring Animal Theme
Crocodile, flamingo, snake, shark, bat, hawk, bear
Luffy's character is also based on a monkey
With Parrot being the most iconic companion for a pirate, it would make sense for Oda to give that animal to a character like Imu
8. Imu living at the top of the red line
The Red Line could be compared to the earth's equator, since it divides the first half of the grand line from the new world.
And parrots live in equatorial rainforests or regions near the equator.
9. Symbol of World Government resembles a toy for Parrots (perhaps a metaphor to the World Government being Imu's Toy?)
10. Popol Vuh Ancient Myth (Imu = Vucub Caquix the demon bird that declared himself as the god of sun and moon)
The whole theme of a devil parrot fighting heroes isn't a new concept, this myth could be where Oda drew inspiration from.
It's an ancient myth where the Hero Twins fights a demon macaw (which is part of the parrot family). The demon macaw, who is the father of both a crocodile demon and an earthquake god, falsely declares himself to be the god of the sun and the moon.
He is shot with a blowgun by one of the Hero Twins, which could be Usopp, and the twins become the true gods of the sun and the moon. The slingshot Usopp uses was historically used to hunt birds, so it would make perfect sense for him to do the final blow. The Hero Twins could be a parallel to the Straw Hat Crew
If you look further into the lore, you can find even more parallels.
11. Why Gold D Roger Laughed
Lastly, the mystery of why Gold D Roger laughed could be explained, if I found out that the world is being controlled by a Parrot I would die laughing too
Later in the series, you can understand why Cobra immediately knew he would be dead after seeing Imu (a parrot) sitting on the empty throne, it also explains why merely seeing him is the world's greatest taboo.
I'm Korean myself and I've personally all done the translation myself (no AI used), thank you for reading this far
All credits to the One Piece Burning Blood Forum in South Korea