The land-dwelling monotreme - an echidna - was rescued from possible death by fisherman Neil "Nobby" Clark at Lake Echo in the Central Highlands in October.

Clark, from Game Fish Tasmania, said he was fly fishing in Lake Echo in waist-deep water when he spotted something odd in the water.

''I thought it was a platypus to start with," Clark said. ''The closer and closer it got to me I thought 'This doesn't look like a platypus at all'.

"Then I saw this little beak sticking up and that's when I realised it was an echidna.

"It made a beeline for me. I picked it up and it was shivering, it was very very cold in the lake - we could feel how cold it was through our waders."

Clark said they were about 200 metres off the shoreline, and the Australian native was heading straight out to the middle of the lake.

"I took him back to the shore and put him on the bank in a nice sunny spot. I think he was happy to thaw out,'' Clark said.

Clark said that while it wasn't unusual to see echidnas in the Lake Echo area - "I think I saw about 40 that weekend" - he'd never seen one swimming before.

''It was like a weird doggy paddle,'' he said of the unique stroke.

He said the lake's water levels were down, and guessed that the echidna might have made an error in judgement in crossing a creek.

"He's got himself in a difficult situation, like we all have at some stage,'' Clark said.

"I think we was just happy he ran into someone who was happy to give him a lift back to shore."

The Examiner, Launceston