Dragon

Dragons are, in the Real World at least, mythical beasts with highly variable characteristics, but usually reptilian, winged, and fond of collecting treasure. They frequently breathe fire, and often they are intelligent. In European tradition they are usually Evil or at least not kindly disposed to people, whereas in Asia they tend to be more wise guardian-type figures.

Dragons are commonly found in many different fantasy Continua:

Lord of the Rings
Dragons in Lord of the Rings are very much dragons of the European style, sometimes capable of speech, sometimes winged and sometimes not, but all evil.

Dragonriders of Pern
Pernese dragons are telepathic, teleportation-capable sentient animals, genetically engineered from fire-lizards in order to be an aerial defence force against the microorganism Thread. They bond telepathically with a Human at hatching.

Harry Potter
In the Harry Potter-verse, dragons are a magical animal, extremely dangerous, but not sapient or sentient.