Aurthour Zahhak

Equius Zahhak's lusus, Aurthour, looks like a centaur, but with an udder and a mustache. In addition to being a guardian, Aurthour is Equius' butler, providing him with his own Lusus Milk. Equius cares for and/or respects Aurthour on a certain level, and refers to him as “simply the best [butler] there is”.
Aurthour's species is said to be one of the strongest kinds of lusus, which is why he became Equius' custodian; no other lusus could handle Equius' ridiculous strength. However, Aurthour bruises incredibly often, even as a result of a grateful pat on the head.

Lusus naturae are members of the Alternia's “diverse and terrifying subterranean monster population” HS which take the role and title of custodian HS to young trolls, acting as their guardians in place of the adults sent to fight throughout the galaxy in the name of the empire. Lusii use scent to select a freshly-pupated troll of a matching blood color - shared lusii between ancestors and descendants suggesting the lusus may even be able to identify a particular bloodline - and together the pair emerge from the brooding caverns and use “CARPENTER DROIDS” HS to build a hive for themselves. In their above-ground lives. The lusus behaves as a lifelong bodyguard, caretaker, and visceral sort of mentor, while the young troll must learn to function as a sort of zookeeper.” The looking after of a lusus is highly important in troll society; the death of a lusus results in the culling of the young troll. Still lusus remains with their troll for life, well into maturation and their job off Alternia, as indicated with the relationship between Redglare and Pyralspite. Lusii are referred to with the same gendered language as their wards, though in most cases just how much meaning the concept of gender has when applied to such a monster isn't fully clear; for the most part lusii are incapable of communicating verbally with trolls outside of very special circumstances.