Lava Lamp is a recommended character recommended by simondomino in Episode 14. He/She was seen, along with some other recommended characters jumping in a vat of hydrochloric acid, trying to retrieve Bally and Marble from it.
Lava Lamp is based of the real life lava lamps. He/She has what is presumed to be plum and violet coloured wax inside, with a dark gray holder and top. Unlike the real life counterpart, however, Lava Lamp doesn't seem to need heating from a light bulb, or rather anything to have the coloured wax working.