After it is cured, and off gasses it really shouldn't be toxic to the animal, unless the snake finds some way to ingest it I wouldn't think that an epoxy could leach much into a humid environment, after all, certain epoxies are used to seal tubs and such. If you are worried about it you can go over it with a coat of drylok. When dried it is tough as nails, 100% water tight and non-toxic.