Toad (as opposed to tad) poles can be toxic, depending on the species. Certainly Bufo marinus (marine/cane toad) is toxic in the adult and the egg and apparently the skin of the toadpole is also bad. From what I've seen fish seem to know this and not try to eat them, or I've seen JD's suck them in, chew them around then spit out the skin (after swallowing the innards).