Slime snails
Slime snails were a species of snail living in the Water Caverns behind the Five Falls. They were domesticated by the white trogs, who used the snails for many purposes.
The snails produced an incredibly sticky slime, as well as an oily grease that neutralised the effects of the slime. The trogs could force a snail to eject this oil by pulling one of its feelers. They varied greatly in size; the largest ones being the size of a bull hammelhorn, and the smallest being able to fit in the palm of your hand.
Uses
The slime-snail oil was flammable, and could be used as fuel. The trogs used upturned snail shells filled with burning oil similarly to braziers, as a source of light in their caverns.
Small shells could be used as musical instruments, such as snail-shell horns, producing a low, booming, sonorous sound, or they could be punctured to make flute-like noises when the wind blows through them.
The slime the snails secreted was used as a glue, and coated cave-spider silk to create strong, yet flexible ropes.
While spidersilk was used for the high-quality robes of the Trog Queen and the highest-ranking females, snailskin clothes were worn by most trogs, and it was also used in capes and curtains.