Terry Pratchett. True (№ 454319)

Tree frogs are native to the humid jungles of Klatch. These nimble, multi-coloured creatures, which excreted the world's deadliest toxin, happily lived in a huge vivarium, which was entrusted to the care of first-year students (like, if anything, it's not a big loss: the general educational level will not suffer too much).