Giant Rats

Description
These big Rats are a good hint, that there is a environmental problem... Giant Rats might be not a big threat in combat, but they carry all kinds of disease with them, and one unlucky bite can be enough to cause a serious infection, which has to be treated at once. Because of this, Giant Rats are less a combat problem, but more are danger to the public health and food stocks in the cities.

Giant Rats usually dwell in caves and dungeons, but can also be found in the wilderness.

Lore
The common giant rat, while not evil by nature, will still enter human camps in search of food. They pose a threat to any dungeon explorers foolish enough to startle them.

- from "The History of Britannia", Ultima IV

Natural agility and sharp teeth are rats' chief advantages. They are not strong and do not hit very hard. The mortal danger rats pose to knights comes from their capacity for passing on noxious germs and substances. Seldom do knights tangle with rats without someone in the group becoming ill with poison. At worst, the result of such an encounter is infection with plague.

- from "The Book of Lore", Ultima V

These voracious, overgrown rodents have evolved over the centuries in the dank, inhospitable sewers that honeycomb the levels below some castles. Having grown immune to most poisons, they are difficult to exterminate. Even a single bite from one of these giants can cause disease or plague.

- from "Compendium", Ultima VI

Over the centuries, the rodents of Britannia have grown ever larger (and hungrier) in the catacombs and tunnels which honeycomb this land. Natural agility and sharp teeth are these creatures' chief advantages. Even a single Giant Rat poses a significant danger for a lightly armed opponent, though an experienced warrior can slay a pack in as many blows as there are enemies. Of the rats which have bred in the Abyss, we have distinguished two varieties. The Giant Tan Rat, commonly found in the drier upper levels, is an aggressive beast with the disgusting tactic of leaping up in order to slash with its teeth at an enemy's throat. The Great Gray Rat is found in the lower depths, where it feeds upon the refuse washed down from higher in the chasm. Consequent to their revolting eating habits, these rats are universally infected with noxious germs which they pass on with every bite. Seldom do our Knights tangle with Great Gray Rats without someone in the party becoming ill. Fortunately, these rats can often be avoided, or driven off with a spirited defense.

- from "Memoirs of Cabirus", Ultima Underworld

Away from towns,  cities,  and  domestic  settings, rats grow to the size of cats or even small dogs. Such rats usually live underground, eating smaller vermin, scavenging refuse left by other cave-dwellers, even  occasionally  cooperating  to bring down larger prey. The giant tan rat is the most common of these creatures, but in the lower depths a thing called the great grey rat has been increasing its numbers. The knight who  reported  this to  us  soon succumbed to an unidentifiable feverish disease, perhaps contracted as an infection  from the many bites found on her legs and torso.

- from "A Safe Passage through Britannia", Ultima Underworld II

Evolution in the series

 * First appearance: Ultima I


 * Last appearance: Ultima IX

Once established, Giant Rats changed very little in all installments they appear in. The only serious change happened in Ultima IX, where Giants Rats became MUCH bigger.