From the Super Mario Wiki
Wind Winders are strange enemies Wario encounters in Beanstalk Way during the events of Wario World. Wind Winders look like green and yellow creatures with opaque white glasses. They hover in the air with the aid of a propeller.
Wind Winders are incapable of directly harming Wario. Instead, they simply blow gusts of wind at him that impede his progress or put him in the attack path of other enemies. As such, Wind Winders are more of a nuisance than a threat. A single Punch or Corkscrew Conk grounds and defeats a Wind Winder.