Up Special Moves are special techniques used by Fox, Falco, and Wolf in Super Smash Bros. series. Fox has used this as his recovery move in all Smash Bros. games, Falco knew how to use it in Melee, and Wolf uses it in Brawl. All of them can aim this attack.
Fire Fox is Fox's recovery move in the SSB series. He will charge himself with fire then launch in whatever direction pointed. In SSB, it was a terrible move, but in Melee and Brawl, it was greatly improved. It can now damage foes while charging and travels farther.
Fire Bird is Falco's version of the Fire Fox. In Melee, Falco used it the way Fox did fire in SSB. In Brawl, it can damage foes while charging and delivers a powerful multi-attack. Ironically, it travels shorter than Fire Fox.
Fire Wolf is Wolf's recovery move in Brawl. Unlike Fox's and Falco's fire attack, he appears to use some kind of "alternate" element, taking the shape of what looks like purple "flames". Interestingly, it is called the Booster Kick in Japan. Wolf will jet forward and hit an enemy with multiple attacks then end with a powerful final kick.