[@Aristocles] At the moment Ive got a range of the standard Fair Folk including- Elves, Dwarves, Fairies, Sirens, Merfolk, Witches, Werewolves, and vampires. All of these beings have their standard humanoid attributes and their way of blending in with Sightless (non magic humans) but Im interested on introducing a bit of a wider range of species and genes. 

Let's use Lizardfolk, this is something I'm not familiar with so bare with me, but how would they use magic? How would they have become something of humanoid form and lizard form? What attributes would pass on to Halflings or a non pure line?