Propeller Shy Guy

Propeller Shy Guys (not to be confused with Fly Guys or Sky Guys) are a subspecies of Shy Guys that first appeared in Yoshi's Story. They fly via a helicopter-like-pack which they carry on their back consisting of a 2-blade propeller (on top of the pack) which spins on a horizontal axis and an 8-blade propeller (at the back of the pack) which spins on a vertical axis. These propellers are powered by the Propeller Shy Guys themselves, who continuously pedal with their feet to remain airborne, although the pedals are not visible.

Yoshi's Story
In Yoshi's Story, Propeller Shy Guys appear flying above Baby Yoshi carrying fruit. The Propeller Shy Guy will continue to fly back and forth in a particular area, but will immediately fly off-screen as soon as Baby Yoshi eats the fruit from the Propeller Shy Guy's hands. Propeller Shy Guys may appear alone, or in a swarm; after appearing they disappear off of the screen, reappearing in the background, and in the foreground again. They can be defeated by Baby Yoshi like any other Shy Guy; with the exception of the elite Black Shy Guy, who has its own special characteristics.

Super Smash Bros.
In Super Smash Bros., they appear occasionaly in the background of Yoshi's Island stage, sometimes carrying fruit.

Super Smash Bros. Melee
Propeller Shy Guys appear as a stage element, and as a trophy. They appear as enemies on the Yoshi's Island: Yoshi's Story stage, carrying food. When attacked softly, or if an object is thrown at them, the Propeller Shy Guy drops his food and flies off the screen; if they are knocked out with an attack, they drop the food they are carrying, and spin downwards off the screen. They also sometimes appear in the background of Yoshi's Island stage from Super Smash Bros., renamed Past Stages: Yoshi's Island.

Super Smash Bros. Brawl
Propeller Shy Guy is one of the many characters to appear as a Sticker in Super Smash Bros. Brawl.