It is unknown if sea dragons are related to dragons, although Sea Dragon Tower is a dragon-shaped tower at Dragonstone in the narrow sea. Sea Dragon Point is a peninsula of the north in northwestern Westeros.
According to ironborn legend, Nagga was the first and mightiest sea dragon, a creature which fed on krakens and leviathans. She was slain by the Grey King, however, and her bones formed part of the Grey King's Hall.
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