The Holstaur, sometimes translated Holstaurus, is a placid monster girl species mainly known for their ample mammaries. They are a subspecies of Minotaur that produce ample quantities of a special milk: a delicious beverage that is used for both cooking and refreshment in the Monster Girl Encyclopedia world. It is one of the few monster products that does not contain large quantities of demonic energy, so it is even found in some Order marketplaces. They are generally content with living a submissive and laid back life, but they have retained the minotaurs' peculiar reaction to the color red.
A Beastman monster that has the characteristics of a cow, and a peculiar black and white fur. It's a subspecies of Minotaur, and through the process of evolution, their violent nature has subsided. These are the ones who chose the path in life to live by obeying humans. Different from Minotaurs, they have a gentle personality and almost never attack people.
However, just like Minotaurs, they're not deep thinkers, and they're spaced-out much of the time. Other than when they eat or have sex, they mostly sleep. A wild Holstaur is always looking for a man to become her husband, and once she's found a man she likes, she lives with him in a human settlement, or nearby area.
A Holstaur will often press her huge breasts up against her husband as an expression of affection. If he responds by rubbing her breasts, it'll be considered a return of affection and she'll be extremely pleased. If she presses her breasts up against him more firmly than normal, it's a sign that she's interested in mating.
On a fundamental level, they respect the will of their husbands, so even if you turn her down, it won't be a problem. However, while they may be docile, they're still monsters that possess an inhuman amount of desire. Continue to ignore them for too long and eventually they won't be able to take it anymore. If this happens, these docile monsters will turn ferocious and assault their husband, forcibly having intercourse with him, and they won't become docile again until all their pent-up sexual desire has been satisfied.
Also, just like the Minotaur, they will become aroused if they continue to see red. Once aroused they will turn violent, as though they are remembering their true nature as a monster, and they will attack human men just like the parent species "Minotaur". In the same way as a Minotaur, even in this enraged state, the monster's instinctive desire for her husband remains strong, and in the case of those that already have a husband, if they see something red and enter a state of arousal, it is said they'll charge off at full speed heading towards their husband no matter how far away he may be.
Even if they haven't given birth, they can still produce milk from their breasts. Not only is this milk highly nutritious and delicious, it also has a stamina-boosting effect. Demand is high among both humans and monsters, so it's a fast selling commodity. They mostly just eat, sleep or have sex, but if living with a Holstaur, the milk alone will be sufficient to support a couple's lifestyle.
- The name "Holstaur" can be split into two words. The first part, "Holst-", comes from the term "Holstein cattle", which is cattle bred exclusively for Dairy farming. The second part "-Taur" coming from "Taurus" which is Latin for "Bull", though in this context it refers to the mythological being "Minotaur", which has its own monster version related to the Holstaur.
- The Holstaur's breasts are so impressive even the Baphomet leader herself cannot make a Holstaur flat chested using a Spell of Pedomorphosis. Instead they become large-breasted lolis.
- The breast size of a holstaur does vary, but KC places a upper limit of them not being bigger than the holstaur’s body (source: Kenkou Q and A thread).
- There are individual differences, but the breasts of holstaurs normally start to noticeably grow during kindergarten age. By elementary school age they are already oppai-lolis. (source: Kenkou’s Japanese Q and A).