October Monster Challenge 2011
From Japan, The Umibozu.
A bizarre water-type Yokai that forms itself from the water, and can grow to immense sizes as the ocean is its source of power. It favors brute force and intimidation to attack ships with the force of crashing tidal waves.
My rendition of this yokai is to have it as a water zombie in the glowing eyes, while using the water to make its body have some shape, yet blends itself together enough to make it capable of changing form.