Ms Castle said the penguins were "not very happy" about their jumpers, but they were needed for their own protection.
A consignment of emergency woolly jumpers have been sent to the Australian island of Tasmania to help protect a colony of penguins from oil spills.
Hundreds of volunteers started knitting when a conservation group warned that Australia's population of fairy penguins - also known as little blue penguins - was under threat.
About 1,000 of the jumpers, which cover the penguins from neck to foot, have been specially knitted, based on a pattern provided by the Tasmania Conservation Trust.
"They have come from everywhere, even as far away as Japan," Trust spokeswoman Jo Castle said on Monday.
"Someone in New York asked for a pattern, but we haven't received it yet," she said.
Protection from toxins
The penguins, which are indigenous to Australia, live on a small set of islands near a shipping route and are often hit by oil slicks.
Ms Castle said the penguins were "not very happy" about their jumpers, but they were needed for their own protection.
The jumpers stop the birds preening themselves and swallowing the toxic oil, before their feathers get washed.
A copy of the pattern has been posted on the Trust's website.
Ms Castle said many of the knitters were old ladies in nursing homes.
Some of them knitted in their favourite football team colours, while others stuck to more typical penguin colours. Amongst the collection is a black-and-white tuxedo, complete with bow tie.
However, fairy penguins usually have dark blue rather than black plumage on the upper parts of their body.
The jumpers are only 40cm high to fit the tiny birds - fairy penguins are the smallest of the species.
The Trust are hoping to secure another 2,000-odd jumpers.