Super Dragon (スーパードラゴン, Sūpādoragon) is Yoshi's Final Smash. When Yoshi grabs a Smash Ball and performs this move, it makes him grow wings, which makes him capable to fly freely. Yoshi can also deal about 8% damage by touching his opponent. If no buttons are pushed for about three seconds, Yoshi will start to breathe a continuous stream of fire which causes very heavy damage (up to 66%). In addition, he can shoot fireballs that do about 17% damage each, by pressing either the standard attack button or the special attack button. This Final Smash lasts about 20 seconds.
This move is based on the various powers that Yoshi could get in Super Mario World by holding certain types of Koopa shells in his mouth, or if played as a Yoshi with a colour other than green. Eating a blue shell allowed Yoshi to fly, eating a red shell allowed him to spit fireballs, eating a yellow shell caused him to make mini-earthquakes each time he landed, and eating a flashing shell caused Yoshi to do all three, similar to Super Dragon, but once he spat fire, he would revert back to normal. The mini-earthquakes are not present in Brawl, and Yoshi can breathe fire as many times as he wishes during the Final Smash. The color scheme of Yoshi in Brawl does not affect the attack in any way.
The name comes from Super Mario World as well. If the information block at Yoshi's House is hit after Bowser has been beaten, it will have a message signed by "Super Dragon Yoshi" at the bottom.
 Trophy Description
Yoshi with wings on his back that give him the power to fly freely across the sky. In this state, he can spew giant fireballs. He is more mobile and powerful, but the inertia makes movement quirky, so it takes some skill to master flight. Yoshi returns to a normal state after a set period of time has passed.
"Sprout wings and fly. Yoshi will spew fire on his own, but you can launch fireballs on command with any attack button."