Hidden Coin

Hidden Coins (also known as Dash Coins) are a special type of coin that have been seen in the New Super Mario Bros. games, Yoshi's New Island, Super Mario 3D World, Captain Toad: Treasure Tracker, Super Mario Run, and Super Mario Odyssey. Hidden Coins are somewhat rare, and they appear in only a few levels.

Description
Hidden Coins first appear as outlines of coins; if Mario or another character passes through the outlines, they will then turn into regular coins after a moment. In New Super Mario Bros. Wii and New Super Mario Bros. U (and its Nintendo Switch port), the coins appear with a quieter sound effect once passed through. Hidden Coins are commonly seen in Coin Battle levels.

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 will be collected when the player hits the ? Block. Hidden Coins also appear in Captain Toad: Treasure Tracker, where they behave like in Super Mario 3D World.

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.

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.