This rear-fanged snake (a viper mimic) was found on the road at night 30 km northwest of Filadelfia. Like the hognose snakes of North America (Heterodon ssp) it inflates its neck to look more menacing and it also feeds on toads. It closely resembles the Neuwied's Viper with which it is sympatric.
Found on main road 10 km southeast of Filadelfia. Upon approach, the frog inflated itself and began to sway from side to side. When handled, it exuded a sticky, viscous toxin which immediately began to burn the handler's skin.