Meinastilim

Meinastilim (メイナストイリム), also called a "Child of Change," are a species found in The Abyss. Not much is known about the species as a whole, due to there being only one known specimen, Meinya.

It is suggested by Srajo that Meinya is the result of an attempt by Bondrewd to create an artificial Juusou. As such, it is unknown whether there are naturally existing Meinastilim.

Description
Meinastilim are small mammalian creatures with round bodies, stubby legs, and large feathered ears that they use to fly with. Their eyes have a horizontally slitted pupil, making their faces look somewhat toad-like. Assuming Meinya is not an exception, they are friendly, vocal animals, and can form strong bonds with humans.

Meinastilim have pliant, flexible bones that can undergo a lot of stress. When Meinya was injured, rather than being crushed, an eye was pushed out of its socket, and the intestines out of the anus, before being popped back in with relative ease.

Trivia

 * Taking in the scent of a Meinastilim grants humans a heightened sense of perceiving The Force Field for a short period of time, which Riko and Prushka referred to as "Fuzzy Stuff".
 * Meinastilim closely resemble the real world animal the Desert Rain Frog. It is possible that this species could have inspired their looks, as a video of one went viral in 2013.