(Nathan Richter/Coleman-Rayner)

Mike Tyson was a tough guy in the ring but don't put him next to a koala.

During a promotional tour in Australia this week, the former heavyweight champion was faced with Trace, a koala that Tyson kept at a distance.

"Hey, Trace, look at those nasty claws you have," Tyson said during a news conference in Brisbane, which was captured on tape by Australia's 7 News.

The marsupial - it's not a bear - was brought out for a photo with Tyson, but "The Hangover" star did not want to touch the animal, saying it probably had bacteria in its claws.

"I don't want to be attacked by good animals go bad," he said with a laugh. "This doesn't look well.

"I don't like animals you can't raise. If I can't see them come out their mother, I don't mess with them."

Tyson, 46, also commented on his decision to star in "The Hangover" and "The Hangover II."

"They paid me a good check, that's why," he said. "I was desperate for money."