Comby's body resembles a purple ornate comb with a light-blue, spherical head. She wears a lavender ruff. Her gemstone is located where her nose would be.
Trivia
In geology and mineralogy, "comby" is the term for bands of quartz, spar and other crystals laid down in parallel veins, resembling the teeth of a comb.
While her name is not mentioned onscreen, Comby was named in the credits of "Familiar".
Comby shares the same voice actress as Blue Diamond.
It is unknown if Comby is a Gem-powered object, similar to the mirrorLapis Lazuli was trapped in. However, she does bear a heavy resemblance to the Pebbles.
While Comby may be perceived as small in relation to Blue Diamond, she actually has the height of most average Gems and Greg Universe.