Her wings were dark as cobalt and her claws, crest and belly scales were as bright as beaten copper. Her flame was cobalt in colour. She was of fighting size but still a young dragon and nimbler in the air than her older brothers. Tessarion was three times smaller than Vermithor and not as fearsome a beast as him in comparison.
Tessarion fought Addam Velaryon and Seasmoke in the Second Battle of Tumbleton. Wounded from the battle, the Blue Queen writhed in pain on the ground until sunset. The dying Tessarion was slain by three arrows loosed by Billy Burley at Lord Benjicot Blackwood's word.