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.
This adult hylid was observed climbing on vegetation at night off the main road 25 km northwest of Filadelfia.