I've loved this set so far, but I'd have to say that this is the reveal I've been least excited about. Of the three, I like the priestess the most; the distended belly is very creepy, and I can imagine using her in other contexts as any sort of creepy priestess giving ready to give birth to something Man Was Not Meant to Know. But the alchemist isn't quite working for me; he looks a bit cartoonish to my eye, and from the picture he looks stuck a bit between human and halfling. Maybe he'll look better in hand.
As for Lamashtu, I'm sure she'll have some big fans, but for me it's the sort of mini that will most likely never see the table, both because it'd have to be such a high-level encounter and because she's just not my cup of tea. But I don't begrudge other people some minis they'll love!