As shown in the Badge, Honours and Origins by Mary Denton for the R.A.F. Heraldry Trust.
Blazon:  On a grey monolith a Cockatrice sage-green and dark pink [Upper and Lower respectively] armed combed and wattled Gules [Red]
After approval, signed by King George VI and issued September 1937.
The cockatrice was chosen because in mythology it was the first creature to fly.

World War 1			World War 2
Western Front*	1914-1918		France & The Low Countries	1940
Mons*			Battle of Britain*	1940
Neuve Chapelle			Home Defence	1940-1945
Loos			Fortress Europe	1942-1944
Somme	1916		Channel & North Sea	1943-1945
Cambrai	1917		Normandy*	1944
Somme*	1918		Arnhem*
Hindenburg Line			Rhine
			France & Germany*	1944-1945
Post World War 2
Iraq*	2003
Items marked with * are shown on the Squadron Standard The 3 (Fighter) Squadron Standard showing the Battle Honours