Tail Boo

Tail Boos are Boos with tails granted by Super Leaves that appear in Super Mario 3D Land and the Minion side modes of the Mario & Luigi series. Their tails are white and grey, unlike Tanooki Mario and other tailed enemies, who have brown and beige tails.

Super Mario 3D Land
Tail Boos first appear in Super Mario 3D Land in the level World 4-4. They follow the player and when the player looks at one to stop it, it will perform a tail whip as it stops. They can only be defeated from invincibility granted from either a Super Star or a Invincibility Leaf, just like normal Boos. Certain Tail Boos drop either a Super Leaf or a Statue Leaf upon defeat.

Mario & Luigi: Superstar Saga + Bowser's Minions
Tail Boos reappear as both enemies and usable minions in the Minion Quest: The Search for Bowser mode of Mario & Luigi: Superstar Saga + Bowser's Minions. Tail Boos are flying troopers, and attack by running into enemies. Their special attack, Spin Cycle, allows them to attack enemies by spinning their tails.

Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey
Tail Boos reappear in Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, where they are allies and enemies in the Bowser Jr.'s Journey mode. They return as flying troopers, and they use Spin Cycle again. They are weak against Ninjis.

Super Mario 3D Land

 * North American website bio: "The Tanooki-tailed Boo may still be scared of you when you're facing him—but if you turn around, he'll charge head on, tail swinging."

Mario & Luigi: Superstar Saga + Bowser's Minions

 * Minion Quest: The Search for Bowser profile: A rare type of boo with a tail. Getting hit with said tail really smarts!

Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey

 * Bowser Jr.'s Journey profile: "A rare type of boo with a tail. Getting hit with the swinging tail really smarts!"