Peahat

The Peahat are a race of helicopter-like enemies. They are vegetable-like in appearance and the "helicopter blades" are probably some sort of hardened mineral tissue that the Peahat developed as a protection to deflect weapons as well as a mechanism for flight. They are only active in the daytime, but can produce larvae at night if struck. They can be killed in some games when they are resting on the ground, and in other games, the roots must be struck underneath the blades.

The Legend of Zelda: Ocarina of Time
The Peahats in this game are much larger than their counterparts from earlier games. They litter Hyrule Field, and start up on the attack whenever a traveler comes near. Their appearance has also changed from earlier games, having large blade-like propellers as opposed to the flower propellers they had. They do not attack during the night. But if you attack it while sleeping at night, it will send tiny miniature versions of the peahat to attack you.

The Legend of Zelda: Majora's Mask
Peahats tend to dwell in underground areas, and are the same as the Ocarina of Time Peahats. They are commonly found asleep and behave the same as a Peahat in the night.

The Legend of Zelda: The Wind Waker
Peahats are small and fly into Link to attack him with their blades. These can only be killed with projectiles, since the spinning blades act as a shield against your sword. Another way to temporarily disable their shield is to knock them to the ground with the Deku Leaf and then destroy them with your sword. The game also features a variation of Peahats called Seahats, a flying sharkish fish creature who rushes at passers-by and shrinks when killed.