The current flag of Wales is a bicolour with a red dragon. However the older version of the red dragon on a patch of grass was flew much longer from 1807 until 1953. The current flag of Wales was adopted in during the MOD era, so it is the Welsh MOD flag. It will not be until the year 2105 that the MOD flag was finally have surpassed the original grandfather version of the Wales flag. Also note all six limbs are easily distinguishable in the older version. In the modern Wales flag it looks like only five limbs are visible.
Also there was a daddy version from 1953-1959, that gets no love. The Daddy Welsh flag basically contributed to the background of the modern flag, being a horizontal bicolour element, as found in the modern, Grandson version.