Lore Sjöberg on Gelatinous Cubes:

[quislibet]

"... Here we have yet another monster with no reason to exist in a dungeon-free ecosystem. It's genetically adapted to graph paper, for God's sake! Plus it conveniently fails to either digest or excrete metal, giving an adventurers a reason to kill it and scoop coins from its corpse. It's like some sort of living, deadly, mall fountain."