Full art:

Color:

“At the time it was born, it was redder, but after it began eating Diabellstar’s mana, it started turning pink (in the same way flamingos do)”

Tail:

“Twists/curls (at will)”

Eating mana:

“Its face while eating mana”
Sfx: *Rumbling sounds*

Features:

Top: “It has a mouth, but it can barely be seen”
Bottom: “It has a patagium similar to flying squirrels”
Left: *Zooming sounds*

Fumes:

Can fly:

Six hours after eating:

Diabellstar: *Drained*
Populus: “Refreshed ↑ Revitalized-look ↑”
Bottle: “Water”

Source.

TL note: The “maryoku” that it’s eating means “magic power”, and it can be translated as “mana” or other similar words. Pick whichever you like if “mana” doesn’t feel “yugioh” enough. As another note, the creature does “eat” this mana, not just “absorbs” it.