Giant Slug

Giant slugs are enormous, omnivorous mutants of the harmless garden variety, usually pale gray above and corpse-white below. Their well-developed mouths chew meat as easily as plants, and they coat their food in corrosive spit.

A giant slug can bite for 1d12, but its real weapon is acid saliva spat at one target. It eats away any organic matter, plant or animal, deals 4d8 damage (half on a save vs. breath weapon) and forces equipment to save vs. acid or be ruined. The slug never runs dry and can spit every round, but aims poorly. The opening shot lands just 10% of the time; later shots hit 90% of the time at ten yards, minus 10% for every ten yards beyond. A miss splashes 10 feet away from the target in a random direction. The slug itself is unharmed by its acid.

These creatures are tremendously strong and smash through doors and wooden buildings in moments. Without bones, they can also slide through gaps that would stop far smaller hunters, so a party hiding in a stone building may be dismayed to see the slug ooze through the same doorway and start spitting. Each round its rasping tongue tunnels through a foot of soil or half a foot of timber, so ordinary barricades are pointless. Their rubbery, boneless bodies ignore blunt weapons and crushing or impact spells; only edged or piercing weapons and magic hurt them.

Giant slugs live anywhere dark and damp, from abandoned dungeons to swamps and rain forests. They are solitary, have no language, and are barely sentient, reacting only on simple instinct.

Apart from serving as monstrous waste disposals, giant slugs have no known use, and nothing preys on them. They eat plants, carrion and garbage but prefer warm, live flesh. Their appetites are so large that they seldom bother with small animals such as squirrels or monkeys, which they can barely see anyway, and they usually have to top up their diet with vegetation. Sprinkled salt kills a normal slug within 1d4+1 rounds; that is unlikely to work on giants, though certain fabrication or summoning spells might be adapted if someone needed to try. For now they remain a genuine threat in jungles, forests and dungeons.