[8] P. olfersii is native to southern South America, including northern Argentina, Brazil, Bolivia, and northwestern Paraguay.

[3] P. olfersii reaches 1 to 1.5 meters (about 40 to 60 inches) in maximum total length (including tail).

[12] Prey items of P. olfersii include small rodents, lizards, amphibians, and birds,[1][7] especially nestlings.

[14] P. olfersii is a venomous snake, and there have been reports of serious bites causing local and systemic effects requiring medical treatment.

[15] The venom of P. olfersii is highly hemorrhagic, fibrinogenolytic, edematic, and has proteolytic activity 208% higher than Bothrops jararaca, in addition to containing neurotoxic properties.

In laboratory mice, the venom of this species has an LD50 of 2.79 ± 0.58 mg / kg (intraperitoneal), equivalent to the lethality of Bothrops asper.

[9] Patients complaining of snakebite may be given an antivenom for Bothrops snake venom, which is inappropriate for the treatment of Philodryas bites.

[4] The secretion that causes death to prey (or injury to bite victims) is produced in the snake's Duvernoy's gland at the rear of the mouth, and ”chewed” into its prey via a grooved tooth; this unique method of envenomation takes considerably more physical effort, from the snake, than it would with a more lethally venomous species (such as vipers, cobras, mambas, etc.).

More recently, there was a severe case for this species, in which the victim let the snake bite for a long time, allowing it to inject a significant amount of venom.