Propeller Piranha

A Propeller Piranha, originally known as a Hootie the Blue Fish (pluralized Hooties), is a purple species of Piranha Plant that appears in Super Mario World 2: Yoshi's Island and Yoshi's New Island. Propeller Piranhas bear a strong resemblance to Jumping Piranha Plants and Piranha Pests; they attack in a manner similar to the latter, but unlike other Piranha Plants in the games, the Propeller Piranhas are near-invincible enemies for a Yoshi. They were originally named after the band.

Super Mario World 2: Yoshi's Island
In Super Mario World 2: Yoshi's Island, the Hooties' only appearance is in Naval Piranha's Castle, though they are numerous in this level. They hover through the air and patrol a set path, often in pairs, and they typically follow along the edges of platforms, akin to a Spark or Spike Top. Avoiding a Hootie can be difficult as Hooties' paths often take them through small tunnels, forcing a Yoshi to wait for the creature to pass by. They cannot be destroyed by any normal means or defeated by swallowing them with a Yoshi's tongue, but throwing an egg stuns them by rotating for two seconds.

A blue watermelon or red watermelon can temporarily defeat Hooties, but they respawn. A POW Block can defeat them permanently. If a Yoshi makes contact with a Hootie, it will inhale the Yoshi and chew on him for a short time similar to that of Wild Piranhas before spitting him out. While a Hootie chews, it repeatedly flashes to a light-blue color with red lips.

Early concepts show that a Hootie was seemingly initially intended to have the same color as a normal Wild Piranha, hinting a connection to the Jumping Piranha Plant.

Yoshi's New Island
Two Hooties appear in Spray Day Mayday in Yoshi's New Island, looking and acting much like the ones in the previous game. They have tongues and larger mouths in this game.

Super Smash Bros. Ultimate
In Super Smash Bros. Ultimate, during Palutena's Guidance dialogue for Piranha Plant, Viridi briefly mentions Propeller Piranhas.

Super Mario World 2: Yoshi's Island

 * Shogakukan guide: 葉っぱをプロペラーのように回転させて、床や壁に沿って移動する. 近よると飲み込まれるが、タマゴを当てるとちょっと動きが止まる. (It moves along the floor and walls by rotating its leaves like a propeller. If you get close to it, it will swallow you, but if you hit it with an egg, it will stop moving for a bit.)
 * Player's Guide: Aquatic pests that inhabit the sewers of Yoshi's Island, Hooties primarily swim in threesomes.

Yoshi's Island: Super Mario Advance 3

 * Shogakukan guide: 葉っぱを回転させながら、ゆかやかべに沿って移動. 近づくと飲みこまれるが、タマゴを当てれば少しだけ動きを止められる. (It moves along the floor and walls while spinning its leaves. If you approach it, it will swallow you, but if you hit it with an egg, you can stop its movement for a little while.)

Yoshi's New Island

 * Shogakukan guide: プロペラがついたパックンフラワー. 一定のコースを周回移動し、近づいてきたヨッシーを食べる. タマゴをぶつけるとその場で回転するので、その間に遠ざかろう. (A Piranha Plant with a propeller. It moves in circles around a fixed course and eats Yoshi as he approaches. If you hit it with an egg, it will spin on the spot, so try to get away from it while it is spinning.)