Worried keepers at Geelong, near Melbourne, thought the eight foot croc, known as Snappy, was on his last legs.
"I thought he was really sick. I thought he was dying," said his keeper Tracy Sandstrom, who runs a mobile reptile display called Roaming Reptiles.
But it turned out the crocodile, who sleeps in a heated bath at night, had been chewing on the water pipes, damaging the filter.
This caused the filter to stop working and pH levels in the water to rise.
Experts believe red algae or tannins from fallen leaves which would normally have stayed out of his water due the filter managed to get in, which combined with the raised pH led to the change in his colour.
In time he should return to his natural green colour.
"There's no change in his behaviour, his aggression, his territorialism. He's still a really nasty crocodile," said Ms Sandstrom.
"It's a collector's item now. Everyone will want one. I should have put him on eBay."Post published in: News