Acid Slugs are gargantuan mollusks whose bodies secrete a corrosive mucus capable of causing mild chemical burns. They appear in Ultima VI, Ultima VII, Ultima VII Part Two, and in the Ultima Underworld series.
Generally found in dark, wet environments such as dungeons, caverns, and swamps, acid slugs have an acute sense of curiosity and will frequently approach travelers to investigate them. Due to the toxic nature of their bodily secretions, however, encounters with these beasts often prove problematic, especially given that their bodies have a tendency to wear on conventional metal weaponry. A canny adventurer, however, will find that these creatures are extremely susceptible to fire and will be able to quickly dispatch them with the aid of a common torch.
|| Though seldom encountered except in the darkest corners of the dampest caves, this featureless creature will secrete its corrosive juices on anything you possess that is metal, thus dissolving it. Painful but superficial skin burns may result from contact with the acid while it eats away at your armour. Conventional weapons have little effect on the monster, whereas a flame will send it fleeing.|
|| Not to be mistaken for the common Slimes of Britannia, the Slugs of the Abyss are gelatinous, amorphous entities. Their extremely small and limited minds are entirely taken up with an insatiable curiosity, and so Slugs are certain to follow any motion they detect. Fortunately for explorers, Slugs have no eyes or ears, and therefore miss much that occurs around them. Of the two varieties of Slug found locally, the Flesh Slug - notable for its pale fleshy color - is the most common and least dangerous. We are not certain if these creatures intend to bite their victims, or if their offensive actions are accidents of their constant writhing. Certainly, no warrior of any experience need fear these pitiful beasts. However, beware the greenish Acid Slug. Though only a little larger than the Flesh Slug, the Acid Slug secretes a noxious vapor which sometimes intoxicates its foes. Despite its fearsome name, this Slug is not poisonous - merely inedible.|
|| This very unpleasant creature tends to inhabit dark places underground. Its skin exudes secretions of acid that can burn flesh and are especially damaging to metal. The best weapon to use against this monster is fire.|
|| Slugs are little to be feared, only avoided. They writhe mindlessly and senselessly from place to place, feeding on whatever they encounter. Disgustingly enough, the flesh slug is a large amorphous blob of gelatin, the color of pale pink human flesh. The greenish acid slugs are slightly more dangerous, as they are capable of spitting acid a considerable distance.|
|| Much larger than its cousin, the common slug, the acid slug prefers habitats far below ground. The creature's slimy covering is quite acidic, burning easily through metal and flesh alike. If it is like its Sosarian counterpart, fire is the most potent way in which to combat one.|
- Acid slugs have been portrayed differently throughout the series. First appearing as pale pinkish blobs in Ultima VI, these beast later came to be shown as white, blue veined creatures in Ultima VII, whereas in the Ultima Underworld games, they were consistently portrayed as green.