Arixmethes

Arixmethes is a kraken from Theros.

History
Obscure legends say that Arixmethes was a major polis that once existed on Theros, and that Heliod smote this coastal city with Khrusor and cast into the sea. In fact, Arixmethes is a massive kraken with the entire city built upon it.

Arixmethes is so large that he is frequently mistaken for an island. While he slumbered, an entire city was built on his back. When he awakened, as the planeswalker Kiora battled the sea god Thassa, he wrought destruction beyond any the hapless citizens of the "island" had ever known.