Made these a while ago. Sketches of my Celemera species in their base form, detailing differences of the young and adults. I also threw in the only difference of a young and adult Celemera in its attack form.

Copy-pasting the description from my original dA submission:

Celemera are rodent-like creatures named after the Starlight Goddess Celestia. They have large ears, indicating that they have good hearing. They have long tails with a large tuft of fur on the tip. Celemera use these tufts to lure attacks away from the main body, as most predators can be distracted by the tuft and go after that. The tuft has little feeling in it and is mostly long fur. Celemera also use the tufts as pillows for themselves and others. Their tufts are very soft. Their fur can be a variety of colours, but their underside is always light gray and their tufts are always a cream colour. They have short snouts which give them a canid look to their faces. Celemera have five fingers and toes on their hands and feet respectively. Their legs are usually curled, similar to rodents, but they can stand quite high on their hind legs, similar to meerkats. They typically walk on all fours, but are capable of bipedal movements.

Young Celemera are small- a newborn can barely fit in the palm of a typical human's hand. They are quite pudgy during their young years, but otherwise look like their parents. As they get older, they elongate, having a meerkat-like look to their body. Celemera are born in litters, with the average litter being 4-5 offspring. Though famed for their shape-shifting skills, pregnant females never transform from the moment they are pregnant to after her babies are weaned. This is for compatibility purposes and prevents defects that could arise from the shape shifting. Celemera mate for life, and both mates become very close to each other.

Celemera are able to shape shift to two separate forms. Their Attack form have deer and wolf like qualities, and they notably have long horns with a bayonet tip. Adults and young look the same, though adults grow and extra branch on the horn. Attack form Celemera are based off unicorns.

The other form they can shape shift into is a long, feathered serpent-like creature, based of the Quetzalcoatl. Their wings replace their limbs and are large, allowing for gliding for long distances. This form is rarely seen, and mostly mentioned in Celestia myths, usually with the Celemera as her mounts.