The Fooz is a mosquito-like creature. They are only found in the Crystal Cave or spawned from the Veezofooz. The Fooz are not always evil, if you manage to find a Fooz Egg you can hatch one for yourself and he will follow you and help you fight enemies.
The Fooz will follow you dealing damage on contact.
On death the Fooz has a 0.01% chance to drop a Fooz Egg. Basically you won't ever get one.