"The offical squadron name is 'Thunder Eagles'. The squadron was well known by the enemy in Vietnam. However there is no word for 'eagle' in Vietnamese so the enemy refered to them as 'thunder chicken'. The squadron members still keep this informal name in tribute to those who have gone before."
Nickname for the V-22 Osprey: "The nine Ospreys of the new Marine Medium Tiltrotor Squadron-263 will carry the "Thunder Chicken" call sign to honor the famed Thunder Chicken helicopter squadron during the Vietnam War."