Dragon Coin

A Dragon Coin is a large coin that first appears in Super Mario World. It has a picture of a Yoshi's head imprinted on it.

Super Mario World
In Super Mario World, there are at least five Dragon Coins littered around most levels; some levels, such as Castles, Ghost Houses, and Fortresses, have no Dragon Coins in the original SNES version). Collecting each one makes a unique sound effect, and it is also counted as one coin. The first four coins collected in the game give 1000, 2000, 4000, and 8000 points, respectively; collecting five of them awards the player an extra life. Yoshi's Wings can be used to access certain auto-scrolling Coin Heavens where five Dragon Coins can be found.

On rare occasions, one may encounter six or more Dragon Coins in a single level; every Dragon Coin after the fifth will also award an extra life. In these levels, going through a Warp Pipe to a new area causes all remaining Dragon Coins to disappear if Mario or Luigi has already collected at least five of them, making the remaining ones unobtainable. Chocolate Secret is unique, as it contains only one Dragon Coin in the SNES version of Super Mario World for unknown reasons.

Super Mario World: Super Mario Advance 2
In the Game Boy Advance port of Super Mario World, Super Mario World: Super Mario Advance 2, Dragon Coins have a slightly bigger role. They now appear in levels that did not originally have them, and the number of Dragon Coins acquired is recorded on a menu. If the player collects them all, a cutscene will play showing all of the collected Dragon Coins falling from the sky and being stacked together; afterwards, a giant Dragon Coin appears, and Yoshi eats it and lays a Yoshi's Egg, which hatches into a giant coin with Peach's face, resulting in all of the Dragon Coins in the game having Peach's face imprinted on them instead of Yoshi's.

Game & Watch Gallery 4
In Game & Watch Gallery 4, a Dragon Coin is used to represent five KOs in the modern version of Boxing.

Other appearances
Dragon Coins were originally going to appear in Super Mario World 2: Yoshi's Island, but they were most likely replaced with Smiley Flowers, due to them being mechanically similar. The sprite for them was completely removed from the Game Boy Advance port, Yoshi's Island: Super Mario Advance 3. In WarioWare: Get It Together!, Dragon Coins appear in the Super Mario World microgame.

Super Mario World

 * Wii U Virtual Console manual description: "Collect five Dragon Coins in a course to earn an extra life."

Trivia

 * Most of the games in the Yoshi franchise such as Yoshi's Safari, Super Mario World 2: Yoshi's Island, Yoshi's Island DS, and Yoshi's New Island feature Coins with a Yoshi's head on them rather than the normal coin design. The Coins in Yoshi's Crafted World feature a depiction of a Yoshi Egg instead; however, the larger 10-Coins depict Yoshi's head, similar to Dragon Coins.
 * In the Nintendo Power Advance Guide, the symbol for the Dragon Coins denoting where they are located in a level is drawn with a three-tined fork instead of Yoshi's or Peach's likeness.
 * The sound effect for obtaining an Advance Coin, Star Coin, or color coin is the Dragon Coin sound effect from Super Mario World: Super Mario Advance 2.
 * In New Super Mario Bros., the same sound effect is labelled as "SE_OBJ_GET_DRAGON_COIN", further suggesting that they replaced Dragon Coins in the final game.
 * The Plessie Medals found in the Bowser's Fury campaign of Super Mario 3D World + Bowser's Fury resemble Dragon Coins.