Eventually, I intend to edit the mess below into something coherent. Until then, I ramble:

• Starbeasts are extra-dimensional beings that, while not forged of pony magic, utilize a similar magical spectrum.
• They come in many varieties, but always correlate with an animal constellation. Amazingly, while they have easily identified sexes, any starbeast may successfully mate with any other, the result of which matching the type of the mother. Additionally, all hatch from eggs.
• Starbeasts look like they are full of stars, galaxies existing under their fur or feathers.
• They are not organic, but magic and energy and bleed starlight if cut or otherwise injured.
• They are also all omnivores, redefining the term by being able to convert to energy anything they swallow, be it organic or inorganic. They do have preferences when it comes to taste, though.
• Starbeasts can change their size, moving more or less of their bodies into extra-dimensional spaces. The more of their bodies they expose to our plane of existence the worse they can be hurt by attacks, so they have been known to only grow over time when owned as their bond with their master rises or their comfort with their environment grows. Fully mature starbeasts can shift their bodies in and out of this plane at will. Certain spells and alchemical potions can force a starbeast to retreat entirely from our plane of existence and fully into their extra-dimensional space. Mature starbeasts can use this ability to fully retreat into other space in order to seemingly "teleport" from one place to another.
• They domesticate fairly easily compared to most wild animals, particularly magical ones, though given their appearance, power, and rarity, they have rarely been tamed.
• Starbeasts are magically-sensitive. They also frequently have a trait or ability not shared with others of their kind. This unique capaicity is most frequently noted in domesticated starbeasts and, coincidentally, frequently seem to provide some capacity that their masters lack.

Starbeasts can survive in space. They do not need to breath and are highly resistant to radiation, and can propel themselves though it by various means... those with wings seemingly able to fly, those without instead swimming.

Akasha's starbeast, a male Gallus named Starwing, has the ability to charge and fire a "star beam" that has an unknown, but seemingly devastating, effect. No other starbeasts were known to display this ability.

• He also had very sharp claws, injuries from which would hurt far more, and take much longer to heal (or far more magic to heal), than would be expected. This is due to their hyber-dimensional nature, the damage "bleeding in" from the other spaces over time. Injuries caused by the claws were otherwise typical in nature.

Instances of starbeasts:

• The zebra Akasha was known to have a starbeast rooster known as a Gallus.
• The zebra Jyotis was known to have a starbeast hound known as a Canis Minor. Jyotis is said to of had a bad memory and her Canis Minor was known for his uncanny ability to immediately find anything or anyone she needed.
• (Jyotis was Akasha's great, great grandmother, stories of which tell of her having a small starbeast dog she simply named "Starry" that would follow her around.)