An echidna stolen from a nature reserve's breeding program on the Gold Coast has become the proud mother of a puggle.

The short-beaked echidna named Piggie was taken from a Currumbin Wildlife Sanctuary (CWS) enclosure in early August and recovered a few days later.

Shortly after her return, keepers paired Piggie with breeding male Spike and soon discovered she had a single egg in her pouch, which hatched on September 29.

CWS senior mammal keeper Alice Roser said it was a nice surprise.

"[It's] like a little bundle of jelly at the moment, [with] some very, very small spines coming through," she said.

"Its eyes have opened up so we can see [its] cute little beak and little eyes.

"[It's] pretty cute at this stage."

Normally echidnas will not lay eggs if they are stressed and keepers said the puggle was a sign of Piggie's recovery from her kidnapping ordeal.

"We left it a month and we watched her really, really closely [then] introduced the male to tentatively see whether it would be successful or not," Ms Roser said.

"She's only had one [puggle] previously so we were a bit cautious and just thought we'd see what would happen anyway."

The puggle currently weighs 620 grams but the mammals can grow up to six kilograms.

"We don't know if it's a boy or girl; you can't tell by looking at them," Ms Roser said.

"It's got to be surgically done so we leave that till [it's] about two years of age."

The puggle will remain in the sanctuary's research program.

"Eventually we would hope that this one could be definitely used for encounters with the public," Ms Roser said.

"[Piggie's] pretty special to us here, so it's nice that we can share that."

The CWS is running a public competition to name the puggle.