Notice Fox McCloud's legs? Or, to be more exact, his lack of them? Yeah, it looks like Fox and friends all have metallic legs. It seems like a random detail they added to make the characters look cooler, but there's a disturbing explanation for it. In real life, fighter jet pilots and astronauts have to wear a G-suit -- tight clothing that prevents gravity from making blood rush into their legs. Without a G-suit, they'd just pass out, and studies have found that pilots are at least twice as bad at their jobs while unconscious.
However, the Star Fox games are set in a futuristic society populated by fashion-conscious anthropomorphic animals. The implication is clear: They had their legs amputated as a way to deal with intense G-forces that didn't involve sacrificing their precious open blazers.
The only question now is: Did "little fox" have to go, too?
And before you argue that the ships' G-diffusers take care of the gravity problem, let us pre-emptively outnerd you by pointing out that this feature wasn't introduced until Star Fox 64 (at which point Fox and pals probably felt kind of silly). And sure, Star Fox Adventures showed the characters wearing pants and boots, but that game wasn't developed by Nintendo, plus they could still have robot legs under there. Also, this would explain why Fox is so fast in the Super Smash Bros. games -- he's a freaking cyborg.
And we thought Jigglypuff's blatant steroid use was the biggest scandal in this tournament.