3-Up Moon

A 3-Up Moon is an item that first appears in Super Mario World. It is a yellow, waxing crescent moon that has a happy facial expression. Being an extremely rare item, the 3-Up Moon functions very similarly to the 1-Up Mushroom, but true to its name, it rewards the player with three extra lives instead of one when collected.

Super Mario World / Super Mario World: Super Mario Advance 2
The locations of the 3-Up Moons in Super Mario World and its reissue are as follows. If the player replays the level, the moon disappears from where it was until the game is reset. Most but not all 3-Up Moons are accessible only if Mario or Luigi is utilizing his Cape form.
 * Yoshi's Island 1 – On a Cloud Block near the middle of the stage, up to the left of the row of Cloud Blocks and a block containing a 1-Up Mushroom.
 * Donut Plains 4 – On a Cloud Block above the Goomba area, near the item block.
 * Vanilla Dome 3 – On a ledge above the area with the hidden feather block.
 * Cheese Bridge Area – Between the regular exit and the secret exit. Mario or Luigi must use the Cape or jump off a Yoshi to get it.
 * Forest Ghost House – In the exit screen of the secret exit, just before the player exits the stage.
 * Chocolate Island 1 – On a Cloud Block above the first bowl-shaped valley area (Mario or Luigi must take the first Pipe Cannon).
 * Valley of Bowser 1 – Beyond an area with Munchers, above the place where Mario or Luigi starts from after touching the Midway Gate.

Additionally, the moon seen in Star World resembles a 3-Up Moon.

Super Mario Advance 4: Super Mario Bros. 3
In Japan, players with an e-Reader could scan the blue switch card to replace 1-Up Mushrooms with 3-Up Moons in Super Mario Advance 4: Super Mario Bros. 3. A 3-Up Moon is also hidden in the World-e level Slip Slidin' Away, and it can be reached only if the player is equipped with a flight power-up.

New Super Mario Bros. U / New Super Luigi U / New Super Mario Bros. U Deluxe
3-Up Moons reappear in New Super Mario Bros. U and New Super Luigi U. They are found within 3-Up Moon Blocks, and a total of four 3-Up Moons can appear from each (depending on how many players are playing). They can appear only by using Boost Mode; tapping a 3-Up Moon Block on the Wii U GamePad screen makes it visible for players to hit.

In the Nintendo Switch port of the games, New Super Mario Bros. U Deluxe, with Boost Mode removed from the original game, 3-Up Moon Blocks were also removed. The 3-Up Moons instead replace 1-Up Mushrooms within blocks if Toadette hits them, although other players can still collect the 3-Up Moons when released. In New Super Luigi U exclusively, the red Toad Houses have 1-Up Mushrooms replaced by 3-Up Moons.

Game and Watch Gallery 4
In Game & Watch Gallery 4, 3-Up Moons appear in the Modern version of Fire, where they come out of Yoshi Eggs and give multiple points when bounced. 3-Up Moons also appear in the Modern version of Rain Shower, where they are caught to fill a meter that, when filled, causes Bowser to fall and gives the player points. This is the only game where they do not have mouths.

Mario Family
In Mario Family, there is a sewing design of a 3-Up Moon.

Mario's Game Gallery / Mario's FUNdamentals
In Mario's Game Gallery and Mario's FUNdamentals, the 3-Up Moon appears in the Dominoes game, representing the number two.

Super Mario-kun
The 3-Up Moon makes an appearance in Super Mario-kun, starting from volume 2. It serves a different purpose, powering up Mario rather than granting him three extra lives. In the second volume, Mario is transformed into Moon Mario, and in the third volume, he is transformed into 3UP Mario.

Trivia

 * Moon Coins in New Super Mario Bros. 2 and Mario Golf: World Tour have an imprint of a 3-Up Moon on them.
 * In Super Mario Maker 2, the appearance of the Moon in the Super Mario Bros. 3 and Super Mario World game styles resembles a 3-Up Moon.