Tornado

Tornados are mentioned only once, and not in the main series, but rather in "The Complete Book of Dragons." "Wheeling by their side, slaloming sinuously through the jutting rocks of the islands, as neat as threading a needle, are the Tornados and the Rocket Rippers, and the odd rare glimpse of a diving Phantom." This passage is introducing the Sky Dragon class chapter in the book. Therefore the Tornado is a Riding Dragon in the Sky Dragon class, and must be rather sleek-looking.

It is possible the author meant this dragon to be the Hurricane, which is a Riding Dragon species mentioned in "How to Betray a Dragon's Hero" (2013).