Cucco Cuccos are chicken like creatures, and "cockadoodledoo" like a rooster. In every game, cuccos summon a flock of cuccos to attack you, if you hit them too many times.
A Link to the Past
Ocarina of Time
Cuccos can be used to float gently down to certain places, and are used to obtain many heart pieces, and even a bottle. However, if hit by the sword one too many times, the cucco will "cockadoodledoo" and a massive swarm of cuccos appear. The best way to escape is to quickly enter a building. You won't nesisarily die, but you can lose a lot of your hearts. Its just a good idea to not attack them.
Cuccos can be used for the same reasons as in ocarina of time. If you hit a Cucco enough with your sword, you can take control of it for a short while.