Character coin

Character Coins or Baby Coins are coins that the Yoshis can collect in Yoshi's Island DS. The Yoshi can only collect a Baby Coin with the baby on Yoshi's back that is seen on the coin. Collecting all eight Baby Coins in a world (or all seven in the case of world five) unlocks a mini-game in the game's Hard Mode. The 39 coins in the game are evenly distributed to 13 each among Baby Mario, Baby Peach, and Baby DK.

Levels with Baby Mario Coins

 * 1-1
 * 1-4
 * 1-6
 * 2-5
 * 2-6
 * 2-8
 * 3-3
 * 3-7
 * 4-4
 * 4-7
 * 4-8
 * 5-1
 * 5-5

Levels with Baby Peach Coins

 * 1-2
 * 1-3
 * 1-5
 * 1-8
 * 2-1
 * 2-3
 * 2-7
 * 3-2
 * 3-6
 * 4-1
 * 4-5
 * 5-3
 * 5-4

Levels with Baby DK Coins

 * 1-7
 * 2-2
 * 2-4
 * 3-1
 * 3-4
 * 3-5
 * 3-8
 * 4-2
 * 4-3
 * 4-6
 * 5-2
 * 5-6
 * 5-7

Trivia

 * There were character coins of Baby Wario and Baby Bowser, but they were cut out in the final version of the game. They still remain in the game's coding.