Bucciarati's Gang within the room
Mr.President (ミスター・プレジデント, Misutā Purejidento) is the Stand of Coco Jumbo featured in Vento Aureo.
It's ownership is transferred to Jean Pierre Polnareff during the events of The Requiem Plays Quietly story arc.
Mr. President grants a supernatural ability to Coco Jumbo and as such, it doesn't have a conventional appearance. It is, however, linked to a unique location accessed with an ornate key embedded with a transparent precious stone.
The room created by Mr. President resembles that of a hotel, containing several pieces of comfortable furniture, a functioning television set and a refrigerator holding drinks. It does not, however, include a bathroom[2].
Mr. President has no combat ability whatsoever, but the power to have a whole room's space inside a turtle makes it very useful as a mobile hiding spot.
Hidden Room: When one places a special key into the depression located on Coco Jumbo's shell, they can access a room "within the turtle"[3].
By simply approaching the hand on the key, one can "sink" inside Coco Jumbo and find themselves in a plain room inside the animal[3]. Inversely, by only raising the arm, the room's occupant can exit the turtle[2]. Removing the key from the shell's depression forcibly ejects the room's occupants[4].
The transparent jewel on the key allows people to peek from either side of the room's ceiling, although those outside may see them as very small, while those inside will see people many times taller than them.[5] It may indicate that people actually shrink to fit inside Coco Jumbo.
The room doesn't protect its occupants from Stand powers, thus The Grateful Dead's power which affects everything within its range could age Bucciarati's Gang hidden inside the room.[6]
Bucciarati's Gang within the room