|First appearance||Super Mario World 2: Yoshi's Island (1995)|
|Latest appearance||Poochy & Yoshi's Woolly World (2017)|
|Variant of||Shy Guy|
Boo Guys are ghostly-looking, Boo-like Shy Guys that first appear in Super Mario World 2: Yoshi's Island. They are white and wear the same masks as other Shy Guys, and have a wispy tail similar to Boos.
Super Mario World 2: Yoshi's Island / Yoshi's Island: Super Mario Advance 3
Boo Guys first appear in Super Mario World 2: Yoshi's Island, and are first found in Bigger Boo's Fort. As with Shy Guys, Boo Guys hover around slowly, and can also spawn from Warp Pipes; colliding with one will cause Yoshi to drop Baby Mario. To defeat a Boo Guy, the Yoshi can stomp on it or swallow it to make Yoshi Eggs. The Boo Guy can also be spat out causing it to roll on the ground and destroy any enemies in its path until it falls offscreen or collides with a wall.
In the background of some levels, particularly fort and castle levels, there are harmful traps that are handled by Boo Guys; the Boo Guys themselves are isolated within confined spaces in walls. Boo Guys that handle a ball and chain will drop it on the ground periodically. Once the ball hits the ground, the Boo Guy then takes time to wind the chain to pull it back up, dropping it again once it reaches the top. Other Boo Guys push a wheel in groups to operate a long, revolving spiked ball or other mechanism. Sometimes, Boo Guys are stationed in long rows in the ceilings and pass bombs from one to another, dropping them on Yoshi when he is underneath (Relay Heihō).
Yoshi's Island DS
Boo Guys reappear in Yoshi's Island DS. Though Boo Guys remain unchanged, only the regular variants appear. The wheel-pushing ones are replaced with normal Shy Guys.
Yoshi's New Island
Boo Guys return in Yoshi's New Island, where they have multiple roles as in their original appearance. Boo Guys that operate traps are seen early in the game and mostly appear in fort and castle-based courses. However, individual Boo Guys that act as enemies only appear in the level Crumble Rock Rumble.
Yoshi's Woolly World / Poochy & Yoshi's Woolly World
Boo Guys return in Yoshi's Woolly World and Poochy & Yoshi's Woolly World and can be eaten by Yoshi, forming a white yarn ball. In the level Spooky Scraps! Don't Get Spooked!, Boo Guys turn into an evil shadow when behind the scraps, which means they can chase Yoshi and cannot be eaten.
Mario & Luigi: Partners in Time
Boo Guys appear in Mario & Luigi: Partners in Time. They are found in Toadwood Forest. In battle, Boo Guys attack by splitting into two transparent copies: one is real, and the other is fake, and only the real Boo Guy can harm Mario or Luigi. They attack by rolling into Mario or Luigi, pointing at the target brother prior to attacking.
Profiles and statistics
Yoshi's Island series
Super Mario World 2: Yoshi's Island
- Shogakukan guide: 食べてから吐き出すと、コウラのようにどこまでも転がってゆく。 (After you eat it and spit it out, it rolls away like a shell.)
- Player's Guide: Basically Boo babies, Boo Guys can be found wherever the Boo family parties down.
Yoshi's Island: Super Mario Advance 3
- Shogakukan guide:
食べてからはき 出せば、コロコ口 転がって 敵をまとめて 倒せる。 天井に 並んでバケツリレーのように 爆弾を 運び、 投下するものもいる。 (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: 幽霊となって空中の低い位匾を漂うヘイホー。攻擊はしてこないが、急いで進みたいときに通行のじゃまになる。すばやく食べて進路の安全を確保しよう。 (A ghostly Shy Guy drifting low in the air. Although they do not attack, they can be a hindrance to your path when you want to proceed in a hurry. Eat them quickly to secure your path.)
Mario & Luigi: Partners in Time
|Mario & Luigi: Partners in Time enemy|
|HP||19 (24)||POW||30 (28)||Defense||30 (24)|
|Experience||8 (10)||Coins||5||Speed||27 (28)|
|Location(s)||Toadwood Forest||Battled by||Anyone||Item drop||Mushroom – 8%|
Super Mushroom – 2%
|Level 5||Notice: Stats in parentheses are from the Japanese and European versions (if they differ from the original American release).|
Group artwork for the candidate welcome party of 1-UP Studio in 2023
Names in other languages
|Yūrei Shy Guy|
Same as Greaper (Mario & Luigi: Partners in Time)
|French||Boo Maskass||Boo Shy Guy|
|Italian||Tipo Boo||Boo Guy|
|Ghost Shy Guy|
|Spanish (NOA)||Guy bú (Yoshi's Woolly World)||Boo Guy|
|Spanish (NOE)||Fanto Guy
|From fantasma (ghost) and Shy Guy|
Boo Guy (Mario & Luigi: Partners in Time, Yoshi's Woolly World)
- The Super Mario World 2: Yoshi's Island Player's Guide describes these enemies as "basically Boo babies", whereas at least one Japanese guide instead calls them Shy Guy ghosts.
- A Boo Guy appears in the concept art of Super Mario Odyssey, suggesting they may have been planned to appear in the game somewhere early in development.
- 「スーパーマリオヨッシーアイランド任天堂公式ガイドブック」 (Super Mario: Yossy Island Nintendo Kōshiki Guidebook), page 5.
- Miller, Kent, and Terry Munson. Super Mario World 2: Yoshi's Island Player's Guide. Page 126.
- 「スーパーマリオアドバンス3任天堂公式ガイドブック」 (Super Mario Advance 3 Nintendo Kōshiki Guidebook), page 23.
- 「ヨッシー New アイランド 任天堂公式ガイドブック」 (Yoshi's New Island Nintendo Kōshiki Guidebook), page 26.
- Omoide Theater, Yoshi Wool World
- The Mushroom Kingdom (Accessed on 2-14-09)