In heraldic jargon - a red dragon passant on a green and white field.
Whilst it is unclear why the Welsh adopted a red dragon as a symbol, it is clear that they have used it for some time. The early Britons probably used it as a battle standard, after the Roman occupation and that it may derive from a Roman Standard. For students of the obscure, the English word "Dragon" and the Welsh word "Draig" both come from the same Latin root "draco" for standard
Some say that the Red Dragon was originally a griffin on the standard of a
Roman legion headquartered in North Wales, but early came to be associated with
the fighting dragons imprisoned by Lludd and Llefelys. The significance of these
was pointed out by Myrddin, the Merlin of Arthurian legend. Two dragons, one white, one red, had fought for many years. The white dragon at first prevailed but in the end the red dragon overcame the white. Myrddin explained that the Welsh would ultimately, after a long period of adversity, overcome the foreign invaders, and maintain their language, lands and freedom. Perhaps that is why the Welsh chose the red dragon
In any case the dragon has become a symbol identified with Wales. A legend recorded by an 8th century historian tells of a fight between a red and a white dragon, which ends with the eventual triumph of the red dragon - representing Wales.
Strangely it was only in 1959, the Queen made the Red Dragon on a green and white, the official Welsh flag.
Land of red dragons - Wales
Y Ddraig Goch, The Red Dragon of Wales, is the
symbol of resurgent Wales.