This psuedo-dragon, known as the Cockatrice (Gallicus halitosis), is thought to be a distant relative of the dragon and the Phoenix, presumably descended from the Archaeopteryx. Due to its venom and appetite the Cockatrice is the most dangerous psuedo-dragon. Sometimes,the Cockatrice form is chosen by the Basilisk, making identification(And hopefully escape.) difficult.
They are 1 to 2 feet high and 3 feet long. The colouration is red or green with a yellow-orange underbelly. Cockatrices have scales on the face and neck, feathers on the body, leathery wings and a crest of long spines. Their call has been charitably compared to a Banshee. They will eat anything that moves, except for snakes and toads which it uses to incubate its gold-coloured eggs. They attack with their poisonous breath, although their beak can inflict a deadly wound as it contains rows of sharp teeth. Cockatrices ambush from under mounds of pine cones, gathered for that purpose. They build their nests in pine trees and the occasional confusion of ships with pine trees has lead to it spreading out across the world. Their foul breath can be bottle with the aid of a trained weasel before being bubbled through springwater. It can then be thrown to stun dangerous monsters without causing any lasting damage.
Mostly found in the Mediterranean mountain forests, although the famous Bogcrow inhabits a swamp in South Wales and some have been sighted as far afield as Newfoundland. There are also cockatrice species in South America, such like the Colo-colo, in Atacama desert.
An alternate look at the Cockatrice mythology can be found at The Compendium Of Vampyres & Other Perilous Creatures.