Board Thread:Spoilers!/@comment-25345262-20160724231934/@comment-91424-20160725013015

Killian Jones wrote: I may not remember correctly... But was it ever confirmed that Lily's father was a dragon, or could shape-shift into one? All I recall is Maleficent saying she was in dragon form herself when she got pregnant, so... x)

It was confirmed. Or at least, strongly implied, depending on how you interpret what Lily says. Here is the actual dialogue, from 422:

Lily: It's a piece of the egg I was hatched from. It's also the only clue I have as to who my father is. Emma: Have you asked your mother? Lily: She doesn't know, either. Emma: What? Lily: It's a dragon thing. You know, it... Happened in dragon form.