Qual'n'Gurtha is a green one-eyed octopus monster. In his own words, he is an "eater of worlds", "devourer of worlds" and "gourmand of galaxies". Beaver releases him from a behind a door which shouldn't be opened in Comic 159. Qual'n'Gurtha declares his intent to end our pitiful universe, starting, in Comic 160, with cakes baked by Steve - but (luckily) the cakes prove more filling than he expects.
Just two of his tentacles are visible in a filler strip (Comic 223).
Qual'n'Gurtha also appears in a guest strip (Comic 226) by Chris Yates. He attempts to buy a can of Dr Pepper, and Steve lends him a quarter. However, he must settle for a can of Pepsi instead, which he is unable to open, as he is poorly equipped for the task (having only tentacles).
In the guest strip, Qual'n'Gurtha is blue instead of green.
With this character, there is now a profile in this wiki for a character beginning with every letter of the alphabet.