SMB2 Mario

SMB2 Mario (short for Super Mario Bros. 2 Mario) is a form that first appears in Super Mario Maker 2, in the version 3.0.0 update. The form is gained via the SMB2 Mushroom, and, as the name implies, the affected character gains the appearance of a character from Super Mario Bros. 2. Alongside the cosmetic change, characters using the form gain the ability to stand on, carry, and throw enemies.

Abilities
When in this form, most enemies are unharmed by jumps; instead, the character can harmlessly stand on them as in Super Mario Bros. 2. However, there are a few exceptions: for example, the character bounces off Wigglers and Big Dry Bones as usual, and stompable bosses such as Boom Boom will take damage instead. While standing on an enemy or object, the player can press while tilting  ↓ to pick it up. Holding will carry the object, and releasing the button while holding something will cause the character to throw it forwards.

When shelled enemies such as Koopa Troopas are thrown, they will slide in their shells as if kicked. Chain Chomps are picked up by their stake, and will attack other enemies while carried. Bob-ombs ignite instantly when picked up. Enemies made larger with a Super Mushroom in the editor can also be picked up, but take longer to lift, like in Super Mario Advance.

In the snow course theme, the character can lift snowballs out of ground tiles. Cloud Blocks behave similarly to soft sand in Super Mario Bros. 2, as they are destroyed after the character attempts to pick up one.

In addition to carrying enemies, the character can perform the charge jump by pressing after holding  ↓ for a bit when on the ground.

Sound changes
Much like the Master Sword power-up, music from Super Mario Bros. 2 plays instead of standard course music while under the effect of the SMB2 Mushroom.

In the ground, underwater, airship, desert, snow, forest, and sky themes, the overworld theme plays. In the underground, Ghost House, and castle themes, the underground theme plays. When reaching the Goal Pole/Axe, losing a life, or obtaining a Super Star, their corresponding themes from the original game play. When a P Switch is pressed, the Subspace music, which is in turn an arrangement of the Ground Theme from Super Mario Bros., plays. The "Peaceful" sound effect plays the credits theme.

The "Boss" and "Final Boss" sound effects play their corresponding counterparts from the game, with the emblems of Bowser Jr. and Bowser being replaced with the sprites of Birdo and Wart, respectively. The "Bonus Music" sound effect plays the character selection music, similar to when the same effect is placed in the Super Mario 3D World style.

When touching a Super Mushroom or another SMB2 Mushroom, the sound effect of touching a cherry plays. Various other sound effects, including jumping, opening a door, defeating an enemy, activating a POW Block, and gaining an extra life, are also replaced with their corresponding Super Mario Bros. 2 counterparts.

Differences from Super Mario Bros. 2
SMB2 Mario's sprites are edited and based on frames from Super Mario Bros. 3 and the Super Mario All-Stars version of Super Mario Bros. 2, with some resemblance to poses from Super Mario Bros.. The idle pose also shows both feet as opposed to only one like in the original game, and has three walking frames instead of two, with one of them edited from Super Mario Advance. However, both walking frames from the original game are still used in Super Mario Maker 2.

Toadette replaces Princess Peach and thus gets a new set of sprites, which are a mix of her sprites from this game's Super Mario Bros. 3 style and Toad's Super Mario Bros. 2 sprites. Toad's idle sprite has his arms bent in a similar fashion to Mario and Luigi's, while in Super Mario Bros. 2, his arms are by his sides; Toadette adopts that stance for her idle sprite instead. As in normal gameplay, everyone's abilities are standardized. Luigi's jump is the same as everyone else's, unlike in Super Mario Bros. 2, where he scuttles.

The player must crouch and hold to pick up objects or enemies, and release that button to throw them, whereas in Super Mario Bros. 2, they can simply press  once to grab and again to throw. The charge required to charge jump resets upon standing up, rather than upon walking or running.

Trivia

 * SMB2 Mario is the only form of Mario that can be overrided using a Super Mushroom, presumably because they use sprites from different games.
 * Taking a Super Mushroom as SMB2 Mario is considered taking damage, since the "take damage" sound effect plays when doing so instead of the "take a power-up" one and the player doesn't gain any points.