COISS is a monster whose carp was mutated.
There is a crack in the stomach, and fish eggs are leaking from there.
COISS has the habit of dispersing fish eggs. and when an enemy appears, throw as a weapon.
Thrown fish egg grows bigger, limbs grow, blue discolor and become coiss.
When it fall in love it turns into pink or turns into gold when it gets excited.
Its a new character cute and little horror.