Are you sure of that name? The U.S. brewer Sierra Nevada makes a barleywine by that name. (high alcohol content, lots of hops for the style)

Some of Sierra Nevada's beers make it to Australia so I wouldn't be surprised to learn that, even if SN Bigfoot isn't currently exported there, the Bigfoot brand name has been protected by copyright or trademarking.

Of course there was the Sail and Anchor brewpub in Fremantle, which back in the late 1980s used their distance from San Francisco and their relative obscurity to make and sell a beer made in the so-called "California common style" under the admittedly logical name "Anchor Steam Beer".

Or the brewery (name reserved to protect the guilty) that thought the producers of The Simpsons TV show wouldn't mind if they made and marketed "Duff Beer" using the name and logo of Homer Simpson's favorite cartoon beverage. They were wrong, and packs of ravening lawyers were released upon them. The surviving examples of 'Aussie Duff' have become rare collectables with a case of 24 cans, according to Wikipedia, having sold at auction for US$13,000.