As its name suggests, Orby is a purple orb, and it appears to be slightly transparent, since it has a visible darker purple on the inside that seems to be constantly pulsating. Orby also has a white line for a mouth (known because it moves when Orby talks), and a white outline (though this may just be there for visibility).
Orby is able to explode, shoot lasers, and launch orb projectiles, all of which it uses for tutorial purposes. It is also able to float around and move through the air at will. Its attacks are similar to those of the Gatekeepers.