Raising Dragons by Bryan Davis
Bonnie Silver and Billy Banister both have a secret. Billy's dad is a dragon, so he can breathe fire. Bonnie's mom is also a dragon and she has dragon wings. Both teens live normal lives-well, almost. When Billy's hot breath sets off the fire alarm, Bonnie comes to his rescue, but now the principle knows there is something strange about them. Which might have been okay, except they realize that the principle is really a dragon slayer in disguise.Will Bonnie and Billy be able to save themselves and their parents from the slayer, or will the last dragons be killed?