They resemble toilets with arms and eyes. Whether they are robots that have been made from recycled toilets and toiletries, or living aliens with an unfortunate resemblance, remains a mystery.
An interesting event in their intergalactic history occurred when, during a rare visit to Capital Planet, one of the visiting dignitaries was mistaken for an extra bathroom by Booster Munchapper (much to the horror of the rest of his team).
Ironically, despite their appearance, they seem to dislike all tongue-in-cheek references to their physiology, along with all forms of "toilet humor".
It is unknown what their world is like or which quadrant it is located in.