Rhacodactylus leachianus is the largest gecko alive, and the one commonly kept species that will genuinely kill a cagemate. Those two facts drive every decision you make about it.
Quick answer
- Around 14 inches total length and 200–300 g — the largest living gecko by both length and bulk.
- Cool: 72–78°F. Sustained heat above the mid-80s is dangerous, exactly as for crested and gargoyle geckos.
- Tall, heavily furnished enclosure with a real hollow to sleep in.
- House singly unless you are deliberately breeding. An incompatible pair ends with one animal.
- Complete powdered diet plus insects. Long-lived — twenty years and beyond.
- Slow to mature, slow to breed, and priced accordingly.
The size, in real numbers
Leachies reach roughly 36 cm (about 14 inches) including the stumpy tail, with adults typically 200–300 g. Snout-vent lengths over 250 mm are recorded from Grande Terre animals. They are heavy-bodied, loose-skinned and powerfully built, which is why they hold the “largest gecko” title on bulk as well as length — a tokay is longer-limbed but nowhere near as substantial.
Locality matters commercially and biologically. Mainland Grande Terre animals run largest; several of the southern island forms, such as Île des Pins, are smaller and stouter with shorter snouts. Locality names attached to captive lines — Nuu Ana, Nuu Ami, Mt Koghis, Yate, Isle E, Pine Isle — describe those source populations, and they are why two leachies can look and price very differently.
The build
| Element | Detail |
|---|---|
| Enclosure | Vertical and large. 18×18×36 inches is a working adult minimum; 24×24×36 is better |
| Furniture | Thick cork tubes and a proper hollow. In the wild they sleep inside tree cavities, and a bare enclosure never lets one settle |
| Temperature | 72–78°F. No basking lamp. Night drops are fine |
| Humidity | 60–80% with a genuine dry-back between mistings |
| Substrate | Moisture-holding bioactive mix; deep enough to absorb a fall |
| Lighting | Low-level UVB is beneficial. They are nocturnal, so it is a supplement, not a centrepiece |
| Housing | One per enclosure. See below — this is not a preference |
Why they are housed alone
Leachianus are territorial in a way crested geckos are not. Two animals that do not accept each other will fight, and because of their size and jaw strength the outcome is frequently a dead or badly injured gecko rather than a chase. Compatibility is individual and cannot be predicted from sex alone.
Experienced breeders do keep pairs together, in large furnished enclosures, introduced carefully and watched constantly, with the ability to separate immediately. That is a deliberate project with a contingency plan, not a default. If you want a display animal, keep one — a single leachie is completely content.
Feeding and temperament
A complete powdered crested gecko diet suits them and can carry the whole nutritional load; appropriately sized insects two or three times a month add enrichment and let you watch a very different behaviour. Dust feeders with calcium. Adults eat less often than their size suggests.
They are famously vocal — growls, barks and yelps, which is where the local name “the devil in the trees” comes from. Handling varies by individual: some tolerate it, some never do, and a defensive leachie can deliver a genuinely painful bite. Nothing about that bite is venomous, as covered in are geckos poisonous; it is simply a large animal with a strong jaw.
The commitment
Leachies are slow. Slow to reach adult size, slow to breed, producing two eggs at a time like other New Caledonian geckos, and long-lived once mature — comfortably twenty years. That combination is why the price sits where it does, and it is the honest reason to think carefully rather than buy on impulse. Lifespans across the group are in how long do lizards live.
If the size or the solitary requirement is more than you want, crested geckos are the same island, the same temperatures, and far more forgiving. The current range is under geckos for sale, and everything ships under our live arrival guarantee.
Common questions
How big do leachianus geckos get?
About 14 inches in total length and 200–300 g as adults, which makes them the largest living gecko species by both length and bulk.
Can leachianus geckos live together?
Not safely as a default. They are territorial and an incompatible pairing can end in a killed or seriously injured animal. Keep one per enclosure unless you are deliberately breeding and can separate immediately.
What temperature do leachianus geckos need?
72–78°F, with no basking lamp. Like other New Caledonian geckos they are cool-climate animals and sustained heat above the mid-80s is dangerous.
What do leachianus geckos eat?
A complete powdered crested gecko diet covers their nutrition, supplemented with appropriately sized insects a couple of times a month, dusted with calcium.
How long do leachianus geckos live?
Twenty years and beyond with good husbandry, and they are slow to mature, so this is a long commitment from the start.