Editing Mushroom Kingdom U

|image = {{tabber|title1=Ultimate|tab1=[[File:SSBU-Mushroom Kingdom U.png|300px]]|title2=Wii U|tab2=[[File:SSB4UMushroomKingdomU.jpg|300px]]}}

|caption = [[File:MarioSymbol.svg|50px|class=invert]]<br>Mushroom Kingdom U across the series.

The starting version, set in a grassland. Features a large main platforms with three smaller [[soft platform]]s above.

Set in the mountains, it features a single rock platform balanced on the tip of a spire; the platform balances like a lever.

Set above pink clouds, features two walled platforms separated by a pit, with floating platforms above the pit and the right platform.

Set in the inside of a tower, features two solid blocks which move along a rectangular rail. In their movement the blocks rub onto each other, and are able to push fighters and [[item]]s.

Several other elements and hazards can appear on the stage, independently of the current stage variation:

*Droplets of water which fall from the sky, soon followed by a giant icicle that [[freeze]]s any player who touches it while it is falling. After striking the ground, icicles serve as platforms which can be damaged and destroyed by attacks.

*Water geysers which spout upwards, acting as extra platforms. Players who touch them will be lifted up. Some of these geysers carry damaging Big Urchins on top of them.

[[Nabbit]] shows up periodically when the stage transforms. He chases after players and tries to catch them in his bag; once he traps a player he attempts to float towards the upper blast line and KO the opponent, much like the [[Beetle]] and [[Boss Galaga]] items. Nabbit is treated as a fighter, and therefore is vulnerable to attacks, grabs, and items - he even takes [[knockback]] proportional to damage - and can be defeated by being launched beyond the [[blast line]]s.

In ''Super Smash Bros. Ultimate'', Ω form and [[Battlefield form]] are similar to the Ω form in ''SSB4''; however, the main platform is now made of the grassy soil found at the beginning of the Acorn Plains portion and is resized and reshaped to match {{SSBU|Final Destination}} and {{SSBU|Battlefield}}, respectively. The three [[soft platform]]s of the Battlefield form are based on the three soft platforms in the Acorn Plains section of the normal form. Oddly, Star KOs can no longer occur here.

With hazards off in ''Ultimate'', Kamek never appears nor changes the stage, which remains in Acorn Plains for the duration of the match. Nabbit is also removed.

[[Kamek]] is a high-ranking member of [[Bowser]]'s army and one of the main antagonists in the {{uv|Yoshi}} series, a [[Magikoopa]] who, in the recent ''New Super Mario Bros.'' games, appears at the beginning of boss battles to transform the arena.

*In ''Ultimate'', [[Nightmare]], [[Andross]] and the [[Squid Sisters]] cannot be summoned from an [[Assist Trophy]] on this stage. Additionally, [[Lugia]] cannot be summoned from a [[Poké Ball]].