It resembles a cylindrical lava lamp full of yellow liquid and orange bubbles. It has two dark orange and red lava blobs shaped like eyes and a large jagged opening under them that looks like a mouth. The top looks like a black bowler hat with a red band around it.
Lava Lamp Guy without his orange aura. Notice how also he's opaque, instead of transparent.
It is the only minion of Bill Cipher that isn't introduced. This is likely because it did not appear until later on, after the other minions had long been present.
Unlike the majority of the Henchmaniacs, Lava Lamp Guy was not involved in the fight against the Shacktron.
In the same scenes, he went through 2 different designs: In "Weirdmageddon Part 1" he was supposed to be a large monster about Zanthar's size, and in "Weirdmageddon 2: Escape From Reality" his design is closer to the final one. Note how in both cases he was planned to wear a fez.
For some reason during "Weirdmageddon 2: Escape From Reality," he lacks his orange aura, and also he's opaque, when he's supposed to be transparent.
