Amphibians
Chacoan Horned Frog
Ceratophrys cranwelli · also called Cranwell's horned frog, Pacman frog
A Chacoan horned frog lies buried in soil with only its eyes showing, an ambush predator built almost entirely around one enormous mouth. It does not appear to distinguish carefully between reasonable and unreasonable prey, striking indiscriminately at anything that moves close enough, regardless of whether the target is realistically small enough to swallow.
Overview
The Chacoan horned frog, Ceratophrys cranwelli, is a rounded, wide-mouthed ambush predator native to grassland and wetland habitat across the Gran Chaco region of Argentina, Paraguay, Bolivia, and Brazil. It buries itself to strike at passing prey of nearly any size.
An appetite bigger than its judgment
The species’ aggressive, largely indiscriminate strike response has made it a memorable subject among keepers, a frog seemingly willing to attempt swallowing almost anything that crosses its narrow field of buried vision.
Status
Least Concern — widespread and stable across suitable habitat throughout the Gran Chaco region, with localised agricultural conversion a long-term concern.
Chacoan Horned Frog: common questions
Why does the Chacoan horned frog have such a huge mouth?
A Chacoan horned frog has a proportionally massive mouth relative to its rounded body, an adaptation that allows it to attempt to swallow surprisingly large prey items, including other frogs, small reptiles, and small mammals, reflecting its role as an ambush predator willing to strike at almost anything close to its own size.
Is the Chacoan horned frog the same as the Argentine horned frog often called a Pacman frog?
No, despite both being commonly nicknamed Pacman frog and sharing a broadly similar rounded body shape and huge mouth, the Chacoan horned frog and the Argentine horned frog are separate species, each with its own specific native range and subtle differences in appearance within the wider horned frog group.
Why does a Chacoan horned frog bury itself with only its eyes showing?
A Chacoan horned frog buries most of its body in loose soil or leaf litter specifically to remain hidden while waiting in ambush, leaving only its eyes exposed above the surface so it can detect and strike at passing prey without needing to move or expose itself beforehand.
Is a Chacoan horned frog safe to keep as a pet?
The Chacoan horned frog is a popular exotic pet valued for its relatively low-maintenance care requirements and dramatic feeding behaviour, but it is also known for an aggressive, sometimes indiscriminate strike response, so careful handling and awareness of its bite risk are generally recommended for keepers.