Daecon is a shapeshifter and can form hybrids such as human/eagle. This is actually the first shift he ever completed, and it was quite a surprise to him.
He is the only living shapeshifter who can do hybrids. All common shapeshifters can do human, one bird, and one mammal. Higher levels can usually do two or three mammals. However, when a shapeshifter takes a form, he is that form: If he changes into a tiger, he's a tiger. If he changes into an owl, he's an owl. Daecon is the only one who can combine forms.
Here is Daecon in his hybrid human/eagle form:
Regardless of what animal my shapeshifters take, their fur/feathers will always be the same colour as their hair as a human. If a shapeshifter has blond hair and his animal form is a bear, he will be a blond bear. If his bird form is a crow he will be a blond crow. This even applies to Daecon - even though he is the most powerful shapeshifter, all of his animal forms are white, just like his hair.
Shapeshifters differ from humans in several areas:
First, they're all male. How they reproduce is explained in the story.
Second, they live a very long time. Hundreds of years,
Third, they have some minor physical variations from humans: Pointed "elf ears", large, pointed canine teeth, and heterochromia (two different coloured eyes) is very common. Also they may have hair or skin colours that don't occur in humans, such as blue, green, violet, etc (a shapeshifter whose bird form is a blue jay will likely have blue hair as a human).