When a man gets on all fours and spreads his asscheeks apart revealing his asshole. With the buttcheeksrepresenting the large ears, the asshole as the one eye, and the hanging cock as the trunk, the lucky viewer gets an image of an elephant with one eye.
An extention on the original term of beaz. If a person from the projects (or Tim Westwood if you're from the UK) wanted to swear then they could substitutethe nasty words (if they were moral) and replace them with ghetto sounding words that rhyme with beaz or beazus.