A pacman frog — a Ceratophrys, all mouth and appetite — wants the least elaborate vivarium of any animal in this guide and the least forgiving one to neglect. It will sit in a single self-dug crater for weeks, so the entire setup reduces to four things: deep damp earth, warmth, humidity, and water shallow enough to be safe.
The tank: small, low and mostly substrate
A 10-gallon tank suits a young frog and a 20-gallon long suits an adult — floor area matters, height does not, for an animal that never climbs and rarely walks. A secure screen lid holds humidity in while letting some air move. Fill the tank with 3–4 inches of coconut-fibre substrate, deep enough for the frog to bury itself completely with just its eyes and horns above the surface. Set the tank somewhere quiet and low-traffic: pacman frogs are ambush predators that startle at vibration, and a frog that feels exposed stops eating long before it looks unwell.
Substrate moisture: the whole game
The coconut fibre should be evenly damp throughout — like a wrung-out sponge, holding together when squeezed without dripping. Too dry, and the frog's skin and burrowing suffer; waterlogged, and bacteria bloom in a warm tank the frog is sitting in permanently. Mist the surface daily with dechlorinated water to hold the moisture, and stir or replace sections of substrate regularly, because this frog urinates where it sits and the crater it lives in is also its toilet. Many keepers replace the substrate monthly for exactly this reason. Keep the substrate free of gravel, bark chunks and moss strands — a lunging pacman frog swallows whatever its mouth lands on, and substrate is no exception.
Warmth and humidity, steady rather than extreme
Aim for 80–84°F during the day with a fall into the high 70s at night. The usual method is a small heat mat on the SIDE of the tank, never underneath — a burrowing frog digs down towards a floor mat and can overheat in its own crater; side mounting warms the air and one wall while the frog chooses its distance. Never place the tank in direct sun, which can spike a small enclosure lethally. Humidity of 70–80% follows naturally from the damp substrate and misting; a simple hygrometer confirms it. No special lighting is needed — a normal room day-night cycle suits a nocturnal ambusher, and bright light only encourages it to dig deeper.
Water: shallow, always
The water dish is the one safety-critical furnishing: wide, heavy and shallow, with water no deeper than the frog's chin when it sits in it — roughly an inch. Pacman frogs are dense, weak swimmers that soak to hydrate and can drown in water other frogs would enjoy. Fill it with dechlorinated water, because this skin drinks what it sits in, and change it every day or two since it will be used as a bath and fouled accordingly. Beyond the dish, furnishing is minimal: a broad-leafed plant at one corner or a scatter of leaf litter gives the frog a sense of cover without anything it can swallow, topple or be trapped under.
A home that cannot pause while you are away
Let the tank run for several days before the frog arrives, misting on schedule, so you know the substrate holds its moisture and the side mat holds the temperature. Once the frog is buried in and feeding, disturb it as little as possible — handling is a last resort with skin this absorbent. The daily care is genuinely tiny, a mist and a water check, but it is also genuinely daily: a dry week can harm this frog. Writing that small routine into KinsLe's Care Pass, giving a sitter clear temporary access to the frog's care details, is how the misting keeps happening on the days the owner is not home to do it.