Thanks for the thoughtful comments! I'm glad I got this posted in time, too. :P I'm glad you liked Lily here. We've seen so little of her in canon that it feels like a challenge to write her. (Although I guess there's a bit more Lily canon now, heh.)

I'm afraid the Tadfoal is JKR's, from Fantastic Beasts (they hatch into a Hippocampus). But I enjoyed coming up with tie-ins to Remus's creature-heavy curriculum in PoA, and there's actually going to be a small plot point regarding Annals of Magizoology in my OotP-era WIP.