Birdfolk

As their name suggests, birdfolk are humanoid or semi-humanoid people that have various avian attributes. There are many different kinds of birdfolk and most of them are not related to each other. While most birdfolk species are not limited to a certain bird species in terms of appearance, they most often look like a specific bird-type.

Kenku

The most common birdfolk amongst the human population, Kenkus are flightless birdfolk often obsessed with their lack of flight. They most often resemble crows or ravens, but it is not uncommon to find Kenkus that look like owls and other, nocturnal birds. They are exceptionally good at mimicking sounds and voices. Additionally, they are masters of copying things, but find it difficult to come up with new ideas. They usually live shorter lives compared to humans.
Most humans know about their existence, but Kenkus are much more common on the Eastern side of the Continent. Most Kenkus live in poverty or in secluded communities, but there are individuals who could strike gold using their abilities to reach power and status.

Cause of Flightlessness

Kenkus have an oral tradition about their history and the event that led to their inability to formulate new ideas and the stripping of their wings. Legend says that Kenkus were once the allies of the Ancient Ones. These Ancient Ones are either the Machinists or the Forebears of the Order texts, but it is not clear which. Kenkus were creative and flight-capable people back then who worked for the Ancient Ones. They made tools and technologies that elevated the Ancient Ones above all others and art that even the gods couldn't replicate.
After a while, the Ancient Ones became more and more controlling of the Kenkus eventually enslaving them, so they decided to rebel. Thanks to their ability to fly and their minds that could produce brilliant strategies that the Ancient Ones couldn't even imagine, the Kenkus started to win their conflict. The Ancient Ones, without a direct way to win, turned to Kaos for help. In exchange for their loyalty, he cursed all current and future Kenkus to become what they are currently. He took away their wings as well as their creativity.
After a long time of this cursed existence, the Ancient Ones died out, but the Kenkus remained.
Every Kenku is taught about this story so that one day they can reclaim their original form.
Stereotypes (by humans):

• Kenkus are often thought to be thieves or criminals
• Most people find it difficult to trust Kenkus
• Most people find it disturbing when Kenkus mimic their voice

Aarakocra

Arch nemeses of Kenkus, Aarakocras are birdfolk who do have wings and the ability to fly. Most kenkus hate them because they are envious of their flight capabilities. They look like humanoid birds, often resembling eagles, hawks and other birds of prey. 
Whilst their existence is commonly known, not many people can say that they actually saw one. Aarakocra live in the Elf Lands and coexist with high elves, from whom the stories spread. Because they don't live together or even interact with humans, no stereotypes have emerged about them.

Kenku Mercenary