The line comes from Gex 2, the platform game starring Gex, a wisecracking gecko who comments on the hazards around him as he explores themed levels. The brown mushy rocks warning fits his habit of mixing useful advice with gross-out humour, which is why players remembered it long after finishing a level. As retro gameplay clips and soundboards spread online, the quote was lifted out of its original level and turned into a shorthand warning for any obviously bad step, keeping its dry, old-school game humour alive for new audiences.