Rivulet

Rivulet is a silly blue slugcat who has pink appendages on their head that look like axolotl gills, specifically made for their rainy, flooded environment. They have "The Mark", which allows them to understand or communicate with Iterators or other creatures with The Mark. Moon(or Big Sister Moon), loves this silly little creature a lot, and this creatures loves her back! They have brought a power orb(or whatever it's called) from Five Pebbles' can to Moon, and has ever since lived with her to keep her company.