The crocodile, called Fatso, bit the 36-year-old man's leg, tearing chunks of flesh from him as he straddled the reptile.Related Links:
He received surgery to serious wounds to his leg and is recovering in hospital, police say.
He had been chucked out of a pub in the town of Broome for being too drunk.
The man, Michael Newman, climbed over a fence and tried to sit on the 800kg (1,800lb) saltwater crocodile.
"Fatso has taken offence to this and has spun around and bit this man on the right leg," Sgt Roger Haynes of Broome police told journalists.
"The crocodile has let him go and he's been able to scale the fence again and leave the wildlife park."
Malcolm Douglas, the park's owner, said that the crocodile was capable of crushing a man to death with a single bite.
"The man who climbed the fence was fortunate because Fatso was a bit more sluggish than normal, due to the cooler nights we have been experiencing in Broome," said Mr Douglas.
"If it had been warmer and Fatso was more alert, we would have been dealing with a fatality."
"No person in their right mind would try to sit on a 5m crocodile, Saltwater crocodiles, once they get hold of you, are not renowned for letting you go."
The man staggered back to the pub bleeding heavily.
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