So this is a Tailrarium:

In the land of Avreinos, there are creatures odd and unlike many other realms in many ways; the common tailrarium is but one of these oddities. Magical familiars and primordial beasts, it is often one will see common tailrariums with sorcerers, warlocks, or other mages.

The common Tailrarium appears as a feline or canine with one to three glass bauble orbs, cubes, or 'other' shapes which often rest as/on/in their tails. The more uncommon the Tailrarium, the more likely one is to find uncommon terrarium shapes.
They sport a hardened glass-bauble set of horns, with teeth and any exposed flesh often matchng the bauble-horns. The more uncommon a specimen, the more likely one is to have more than one set of horns, or even "floats." "floats" are when additional glass-bauble orbs or otherwise shapes magically fix themselves to a part of the beast without touching it.

- Heyas! Thanks for poppi'n in and having a peep at my boi. He's a COMMON Tropical Tailrarium. His magical elements are Sea-water, and Air, which is what results in his unique typing as [TROPICAL]. I'm considering starting to make these as adoptables and mabe even slappin' out a species sheet for others to have easy access to make their own. ^^
As it stands, Tailrariums are an open species and while there isn't much information out there for you guys yet, more will come, don't worry!