An Udderat is about the size of a pony, and resembles a huge domestic rat with a cow's udders underneath. They come in a great variety of rat markings. Considered a low threat when wild, Udderats are usually a benefit to the people of Thistleland due to the properties of their milk.
Udderat milk is highly nutritious, and due to the Udderats origin in The Changed Lands, has two properties that are a blessing, and a curse. In smaller quantities Udderat milk has a strong and potent healing effect, removing minor injuries in seconds and if taken in larger quantities can heal deep cuts with some stories telling of broken bones healing within a day. however, the milk has another, far less beneficial effect. If too much milk is consumed in a short period, a person will show signs of growing their own bovine features, with udders and even possibly cow horns forming in proportion to how much milk a person has drunk. They will also rapidly gain a measure of weight, causing such people to appear overweight. While the effect is usually short lived, the effects can be quite embarrassing, and will often cause a noticeable decrease in agility and stamina.
Most healing potions found in Thistleland have their basis in Udderat milk, often adding flavourings and colourings to suit the buyer's preference. While minor and medium healing potions use normal Udderat milk as their active ingredient, high healing potions in Thistleland usually use either condensed or evaporated Udderat milk as their active ingredient. Such potions are more effective, though will have an increased rate of transformation if several are quickly drunk compared with normal Udderat milk potions.
The transformation effect hints at the Udderats origin in The Changed Lands, and would explain the species wide desire to provide milk to others, normally a symptom of attempting to spread the changing fluid. While all Udderats in Thistleland long ago ran so low of changing fluid inside their milk to fully transform another person into an Udderat, let alone have permanent changes, they still suffer the urge to provide their milk to any person they are able to, causing potential problems for Udderats not regularly milked.
While domesticated Udderats are treated much like traditional cattle, living in stables or fields around the towns and villages of Thistleland, and often providing a population with a readily available supply of daily milk, there are still a great number of wild Udderats, who either have not yet been domesticated, or have somehow left the farms they typically live in. such Udderats are often overcome with their urge to feed people milk, and will aggressively grapple anyone they come across, with the aim to subdue the person and force them to nurse from their udders. While forceful and intent on their objective, much like domesticated Udderats will specimens will generally not cause any serious harm to their victims and once nursing begins will often act extremely motherly to their prey.
While few Udderats have been sighted in The Changed Lands, probably due to their less aggressive nature and temperament compared to other changed creatures, there have been reports that The Changed Lands specimens are still fully infectious, their milk able to turn a victim into another Udderat permanently. The Adventure Guild has yet to verify such reports.