Bakunawa were legendary, unbelievable eel-like creatures who were also commonly known by their nickname "Dragon Eaters", due to their preferred diet being the dragons of Kiston who flew too close to the continent's wide, deep rivers.
About
Called "near-impenetrable" and "solid as bedrock", a single Bakunawa was a large enough sea-serpent that small ships could be devoured whole in an snake like fashion, or even large dragons could find themselves being latched onto and slowly devoured, like a young deer stumbling into a snake's nest.
The Bakunawa had a mysterious connection to the Bakukin, a native species of eel like seafolk who also lived in the waters where a Bakunawa lived.
Because of their strange diet and immense power, a single Bakunawa was typically the top of the food chain in an entire ocean. For example, the one known to live in the rivers that crossed through Kiston was often referred to as "The Dragon Eater", implying only one in the region.