Source: Eulogy for Roslar's Coffer, pg(s). 84–85
Mix couatls are couatls known for the guidance, knowledge, and protection they offer to fledgeling societies. Alongside auwaz couatls, they are one of the most commonly seen couatls on Golarion.
Mix couatls are winged serpents whose scales are dotted with light grey spots and red stripes. The colour of their feathers ranges from deep blue to pitch black, allowing them to blend into a starlit sky. The sounds made by their wings when flapping resemble distant thunder, and those who know of mix couatls find them calming, as a reminder of relaxing summer rains and the couatls' protection. A typical mix couatl is 12 feet long with a wingspan of 15 feet, and weighs 1,500 pounds.
Although mix couatls are gifted with knowledge of their siblings, they do not individually have access to this knowledge; instead, mix couatls can share bits of knowledge with others, even if they themselves are unaware of the full details of the knowledge they grant. Because of this, mix couatls can work together without meeting each other in person, and they also teach this lesson to others.
Mix couatls have very long life spans compared to other couatls, though shorter than that of xiuh couatls. An old mix couatl lays a small clutch of eggs which hatch up to six offspring. Even after their deaths, their legacy can live on for centuries in the form of the knowledge they taught.
Mix couatls are capable predators, but are accustomed to receiving gifts of food from a settlement's harvest. For this reason, according to many stories, earning a mix couatl's favour requires a sweet fruit.
Mix couatls seek out young settlements and offer their knowledge to help them prosper, depending on the nature of the settlement and residents, most commonly knowledge about nature to assist with farming and hunting, leading them to be seen as demigods of the hunt. It is claimed that they taught fire and magic to Golarion's earliest humans, so some also see them as demigods of war, a reputation which mix couatls consider unwelcome.
Individual mix couatls have different beliefs on the exact requirements of a settlement, and do not get along with each other. Settlements aided by a mix couatl are marked with a beacon so other mix couatls would know to avoid them.
While altruistic as a whole, mix couatls are also willing to share dangerous knowledge to cause trouble and shake up a settlement's growth. These challenges often teach valuable lessons to their charges, allowing them to improve in unexpected ways.
Mix couatls often stay with and periodically visit the same settlement for generations, and new generations consider it a great blessing to see a mix couatl once more. They rarely abandon their charges, only doing so when they recognise that they are doing more harm than good.
- Mixcoatl (real-world deity) on Wikipedia