White Shy Guy
From the Super Mario Wiki
White Shy Guys are white colored Shy Guys first found in the game Yoshi's Story. They are friends of the Yoshis, and could be considered the antithesis of the Black Shy Guy, as the White Shy Guys work against their Shy Guy brethren, while the Black Shy Guys are the elite in Baby Bowser's Shy Guy forces. They later reappeared assisting another one of Bowser's enemies (Fawful) in Mario & Luigi: Bowser's Inside Story. A White Shy Guy is also playable in the DS Download Play mode in Mario Kart DS.
 Yoshi's Story
If a Baby Yoshi finds a White Shy Guy in Yoshi's Story, the White Shy Guy will follow behind the Yoshi like a Yoshi Egg, copying the Yoshi's movements until the stage is completed. Indeed, the White Shy Guy will take the place of one the Yoshi's eggs, meaning that the Yoshi can only carry five eggs instead of the normal amount of six. After the stage is completed, the White Shy Guy can be selected in the Yoshi select screen. If selected, the White Shy Guy will equip the helicopter backpack of the Flying Shy Guys and travel to Baby Bowser's Castle in order to rescue any Yoshi that has been captured by the Toadies. However, the White Shy Guy can only rescue Black Yoshi and White Yoshi if the player has completed the game with them. White Shy Guys are usually hidden inside ? Bubbles or ? Blocks in the levels they appear in.
 Mario Kart DS
 Mario & Luigi: Bowser's Inside Story
In Mario & Luigi: Bowser's Inside Story, white Shy Guys appeared in Bowser's Castle, but this time, they are working for Fawful. Mario, Luigi, and Bowser never get to fight them on their own, but when the Sniffle Thwomp faints at the start, three White Shy Guys come in, pick it up and carry it to Bowser.
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