Memphis guard O.J. Mayo claimed his positive test for a banned substance was the result of guzzling a five-hour energy drink. Plausible? Sure. But his excuse doesn't even crack this list:

1. Oh, veal-ly? » Petr Korda's explanation for a 1998 positive test for nandrolone? He ate a lot of nandrolone-fattened veal. But to record the level that he did, scientists claimed he would need to eat 40 calves a day for 20 years.

2. Happy Birthday! » U.S. sprinter Dennis Mitchell said his 1998 positive test for high levels of testosterone stemmed from the previous night, when he'd had five or six beers and, um, relations with his wife a handful of times. It was her birthday after all. Amazingly USA Track & Field bought the excuse. A couple years later he was linked to the BALCO scandal.

3. Hey, I thought it was mint-flavored! » German distance runner Dieter Baumann blamed spiked toothpaste for his 1999 positive test for nandrolone. He even offered a $52,000 reward to catch the culprit. Baumann later was banned for two years. On the positive side he tested negative for cavities.

4. Heaven sent » American cyclist Tyler Hamilton's defense after testing positive in 2004 for blood doping was unusual. He said the foreign substance was from his twin who died in his mother's womb. The U.S. Anti-Doping Agency handed him a two-year suspension in 2005 after a failed second test.

5. Passionate kisses » French tennis player Richard Gasquet tested positive for cocaine in May 2009. But he won his appeal when the Court of Arbitration for Sport bought his excuse: The cocaine entered his system when he kissed a woman in a nightclub.