[Taryon rests his face on his palms, reviewing the spell, going back to the list of definitions, checking the wording of the requirements.]

So...it says that it can be created in an object, not a creature. The wyrmling isn't an inanimate object. However...it says you can turn this into a cube 30 feet wide of rain, so you could also extinguish some of the flames. It won't damage the beast, but it would clear up some of the pathways leading away from the street.

[He stops himself before he speaks of another idea - he'll have to see what Ratchet comes up with.]