Most of the information contained in this section does not apply to queens, and there are some exceptions for workers.
It is important to note that changelings are not arthropods, much less bugs or insects. That doesn't stop them from using such euphemisms as "what the bug", in place of the pony phrase "what the buck", and "love bugs", when referring to prisoners who have gotten married.
Their outer surfaces consist of a chitinous exoskeleton, with a bony vertebrae and skull, and cartilaginous ribcage and limbs. The exoskeleton is thinner at the joints, and softer in other areas, to allow for flexible movements and intimate contact, while thicker around the bases of the legs and chest. In the thicker areas, the exoskeleton develops holes, so as to not weigh the changeling down.
Each changeling has a unique arrangement of these holes, and they stop forming after they reach maturity. As they age, the chitin around the holes will begin to crack, and the thinner chitin will wrinkle, though, only in a select few places.
Changelings have curved horns, with thin ridges running vertically along its surface. These ridges serve an unknown purpose, though I speculate that they are functionally similar to the spirals on a unicorn's horn, allowing the magic to be collected at the end of the horn.
Their eyes have a single lens, though difficult to formally classify. They are fixed into the eye socket, and cannot be moved independently of the head as a whole. They lack distinctive pupils or a blind spot, as the photoreceptors are located in front of the axons that connect to the optic nerve.
Their teeth are blunt, save for the enlarged fangs at the front, which grow continuously, and are a common indicator of an individual's fitness. Larger fangs are considered the height of sexiness, and a changeling with a chipped or missing fang is considered especially attractive, like a scar. Fangs unequal in length are likely the result of having one previously removed, often in a fight.
My associate even once blushed after looking over one of my sketches of him, insisting that his fangs were not that big, but that he was incredibly flattered by the image, and then chose not to heal one of his fangs after it was cut off.
They have retractable frills on the back of their necks, which are extended when trying to assert dominance or engage in a hostile encounter.
Their wings can be vibrated at incredible speeds, emitting humming sounds, which they use to communicate, along with chirping sounds produced by their vocal cords. They all speak the same language, but with different castes using different layers of complexity and nobility of the language.