Perth Zoo has produced the world's first puggle from two captive-born echidnas.
Perth's newest puggle hatched in August, weighing less than a gram, before spending two months in its mother's pouch to eventually be deposited in a burrow when it got too prickly for its mum.
A Perth Zoo spokeswoman said short-beaked echidnas were notoriously difficult to breed, but changes to animal management and their exhibit design, inspired by Philadelphia Zoo, led to a successful result.
"The puggles will remain in their burrows off display until they're about six months old," she said.
"By then they will have a fully protective covering of spines and look just like a small adult echidna."
It is hoped the successful breeding program will assist researchers in attempts to safeguard the future of the critically endangered long-beaked echidna in Papua New Guinea.