Hidden Coin

Hidden Coins (also known as Dash Coins) are a special type of coin that were introduced in New Super Mario Bros. Wii. Hidden Coins are somewhat rare, and they appear in only a few levels.

Hidden Coins first appear as outlines of coins; if a character passes through the outlines, they will then turn into regular coins after a moment.

New Super Mario Bros. Wii
Hidden Coins first appear in New Super Mario Bros. Wii. The coins appear with a quieter sound effect once passed through. Hidden Coins are commonly seen in Coin Battle levels.

New Super Mario Bros. U / New Super Luigi U / New Super Mario Bros. U Deluxe
Hidden Coins return in New Super Mario Bros. U, New Super Luigi U, and New Super Mario Bros. U Deluxe, behaving the same as in the previous game.

Super Mario 3D World / Super Mario 3D World + Bowser's Fury
In Super Mario 3D World and Super Mario 3D World + Bowser's Fury, Hidden Coins are transparent, and they can be briefly revealed by a Ground Pound, or by touching the Wii U GamePad screen or blowing into its microphone, like Hidden Blocks. Hidden Coins are sometimes found on top of ? Blocks, where they are collected when the player hits the ? Blocks.

Super Mario Run
In Super Mario Run, Hidden Coins make their first appearance in Ghost-Door Deception. This time, they appear more commonly than in New Super Mario Bros. Wii. Touching one can reveal a regular coin, a Pink Coin, a Purple Coin, or a Black Coin, depending on the level.

Super Mario Odyssey
In Super Mario Odyssey, Hidden Coins return, working as they do in Super Mario 3D World. They are often placed in areas that are hard to get to without using the Cap Throw. However, they can be seen if a Moe-Eye is captured.

Yoshi's New Island
Hidden Coins also appear in Yoshi's New Island, where they behave like in New Super Mario Bros. Wii.

Captain Toad: Treasure Tracker
Hidden Coins also appear in Captain Toad: Treasure Tracker and its ports, where they behave like in Super Mario 3D World.