I suppose hybrids are on a very case-by-case basis. Fun to think about, though.
@Emma Your making me think! Geez, this is fun! Reproduction depends on the fae. Ents grow from a seed, some hatch, some are born normally, and other are spun by very powerful Fae that understand the beginning mystery. The thing which started Life. It's the Holy Graile and should a Fae know it, they would not use it for fear of the price. Life comes at a cost when making it from the hands of the Fae.
As for genetics, they can cross breed but pure lines are more desirable to some as they are thought to be and usually are more powerful. A cross breed will take after a parent or be a hybrid if it's possible. Ie. Elf and Season-born equals a Powerful Elf with Seasonborn qualities. A pegasus and Unicorn makes a Alicorn.
@Emma
As for genetics, they can cross breed but pure lines are more desirable to some as they are thought to be and usually are more powerful. A cross breed will take after a parent or be a hybrid if it's possible. Ie. Elf and Season-born equals a Powerful Elf with Seasonborn qualities. A pegasus and Unicorn makes a Alicorn.
@Emma There's no catch phrase. if they are a mix it generally doesn't matter. Unless it's apparent.