Falsa Yarará Sapera

Adults of Xenodon merremii are usually 1 m (39 in) or less in total length (tail included). Its color pattern is very variable. Some "red phase" specimens are a uniform reddish tan. Other specimens are pale brown dorsally, with broad dark-brown crossbands, which are edged with black, and are narrower or interrupted in the middle. The latter color pattern resembles that of the venomous snake Bothrops alternatus.

Xenodon merremii occurs in Venezuela, Guyana, Suriname, French Guiana, Brazil, Bolivia, Paraguay, Uruguay, and northern Argentina.

Xenodon merremii preys on insects, frogs, toads, lizards, and sometimes snakes. Like other rear-fanged toad-eaters of the genera Heterodon and Lystrophis, X. merremii uses its enlarged posterior maxillary teeth to puncture and deflate toads which have defensively puffed themselves up, thereby making them easier to swallow.