Vhagar was one of the dragons used by Aegon The Conqueror and his sisters during The War of Conquest. It was named for one of the gods of old Valyria. Vhagar was ridden by Visenya Targaryen.
Duringthe battle that became known as the Field of Fire, for the only time in history all three of the original Targaryen dragons took the sky at the same time. Together, Vhagar, Meraxes, and Balerion the Black Dread killed four thousand men, burning them alive. King Mern died, and with him House Gardener. The army was broken and Aegon I was victorious and during that battle the fire of Vhagar could melt a knight's armor and cook him inside. During The Dance of Dragons Vhagar was ridden by Aemond Targaryen.
After Vhagar died its skull can be found at the Red Keep in Kings Landing.