The Basilisk's(Draco basilikos) status as a dragon is arguable, as some think it a psuedo-dragon while others believe it to be mythical.
The Basilisk is 2 to 3 feet high and 4 feet long. It can take the form of any dragon or psuedo-dragon and is armed with the deadliest bite of any creature(There are no antidotes to its venom,which can melt metal.). Our only descriptions are therefore somewhat variable, although the eyes are always emerald green with flecks of gold and black pupils. The hypnotic stare of those feline eyes is used to draw in its prey, including the unfortunates who made those observations. It is thought that it can speak English but it prefers silence. Their prefered form is the chick of a European Dragon.
They will eat almost anything(Including their own chicks, who must learn to shapeshift quickly.), although they prefer young animals. They also eat the eggs of other dragons but sometimes leave those nests untouched, save their own cuckoo-like egg.
They are apparently frightened of chickens and weasels, although this can not be verified. Mirrors offer some protection, as the basilisk will judge its reflection as being more dangerous than you and attack it instead.
The Cockatrice, and the Basilisk, were once thought to be the same thing.
They are most commonly found in the bluebell woods of England's chalk downlands, although its status as Guardian of Basel in Switzerland suggest a much wider range.
Whichever form they take, venom from the soles of its feet will always poison the ground beneath.
A baslisk in its true, slug-like, form was encountered by the Cook family in Alexandra Gorynytchka's Tibetan ice palace.