These were an adoptable project I worked on a few years ago. Not available anymore, but still really cute!

Other info:

Lifespan: Up to 50 years

Diet: They do best on a diet of fruit or insects, but they can survive on other diets and usually adopt the diet of whatever species they're mimicking. Strictly ruminant diets are beyond their ability, though.

Reproduction: Teacups can lay a single egg every year. Teacups are driven to lay their eggs as far away from their homes as possible and don't stick around to incubate or care for them. This is one time when Teacups keep their own instincts; even ones with sapient-level intelligence find it extremely hard to fight this urge. When asked to describe their reasoning, they say that, for some reason, they feel it would be stifling and outright harmful to the child if they or other Teacups were around during the child's development. Some social Teacup societies buck the trend and actively bring back the eggs of their community members, but they have a lower rate of successful hatches than normal (the eggs are fertile, but the embryo dies before developing completely), so it seems like there is some kind of benefit to the instinct.

Childhood: Teacup Dragons are the world's most successful cuckoos! Most egg-laying creatures will care for Teacup eggs without an issue, and sapient societies consider it extremely good luck to find a Teacup egg. Infant Teacups can walk within minutes of hatching, kind of like deer, and immediately start looking for an animal group to buddy up with. When they find one, they will try their best to fit in. Whether it's due to their uncanny mimicry or something else, it's usually very easy for them to 'integrate' into the broods of other species, and they can sometimes even trigger maternal behavior from animals that don't have their own children at the time. Teacups can adapt to many different species in their lifetimes, but they'll always retain a few instincts and quirks from their very first mimicked species.

Adulthood: Most Teacups live among other species and don't mingle with their own kind very often. Even when they do, they usually don't show the same voracious interest in their kin that they usually do for newcomers. There are a few scattered societies made up entirely of sapient Teacup Dragons; in this case the 'other species' they've chosen to mimic are the adults of their own kind. Most of these societies started out when Teacups mimicked Simians or other troop-based, sapient species, then decided they wanted to cultivate their own society. They point out that Teacups who mimic other species often live subpar lives, trying to adapt to lifestyles that their bodies and minds weren't built for. Other than these unusual groups, it's very hard to say anything concrete about adult Teacups since they're usually extremely different!