Relay Heihō

Relay Heihō are bomb-dropping Boo Guys from Super Mario World 2: Yoshi's Island, Yoshi's Island: Super Mario Advance 3, and Yoshi's New Island.

Super Mario World 2: Yoshi's Island
In Super Mario World 2: Yoshi's Island, they are found stationed in long rows within the ceilings of certain castles. They relay a single purple bomb, dropping it when a Yoshi approaches them. The Yoshi can perform a Ground Pound to startle them, forcing the bomb out of their grip. If they miss, the one who held the bomb will hang its head with an ashamed expression, the one who was supposed to receive it will rapidly look to both sides, and the others will shake their heads. If none of them were holding the bomb while the Ground Pound is being performed, the entire row will shake their heads. They will start over a few moments later. Due to their position, they cannot be defeated.

The Nintendo Player's Guide generically calls them "bomb-throwing Shy-Guys."

Yoshi's New Island
In Yoshi's New Island, Relay Heihō act the same, though they no longer change expression when the Yoshi ground pounds; the game has unused textures for those expressions in its data. They appear in King Clawdaddy's Sewer Castle.

Yoshi's Island: Super Mario Advance 3

 * Shogakukan guide (shared with Boo Guy): べてからはきせば、コロコ口がってをまとめてせる. にんでバケツリレーのようにをび、するものもいる. (If spat after eating, it will roll around and take down enemies en masse. Some line up in the ceiling like a bucket relay to transfer a bomb, and drop it.)

Yoshi's New Island

 * Shogakukan guide: 数体まとまって天井に潜み、下を通過するヨッシーに爆弾を投げ降ろす. 攻擊することも倒すこともできないので、敵というよりはしかけに近い. (Several of them lurk in the ceiling and throw bombs down on Yoshi as he passes below. Since they cannot be attacked or defeated, they are more like a trap than enemies.)