The Battle Kukkus appear to operate a rather idiosyncratic system of archontology, pre-emptively granting the crown prince an imperial numeral while his father is still very much alive and well and throwing bombs at people. Perhaps as a means of circumventing the nomenclative confusion, the prince goes by his nickname, Speedy. He is first encountered in command of the Kukku troops on Polly Mountain 1, and later in the Battle Fortress.
After fighting his way up through the avian soldiers swarming Polly Mountain, Tails finally reaches Speedy, who immediately bolts straight skywards. The fox (with a suddenly infinite flight gague) must pursue the crown prince as they dart amidst the mountain's upper limits. Speedy periodically attacks Tails with a corkscrew dive-bomb from above. There is no means of actually damaging this boss; like Robotnik in Sonic 1's Labyrinth Zone, victory comes simply by making it to the summit of the mountain. At this point Speedy, exhausted, drops the P Chaos Emerald and is shown flying back to the Battle Fortress.
Battle Kukku 16th is fought again when Tails busts into the Battle Fortress himself. Speedy takes the job of penultimate boss, guarding the antechamber which leads to Grand Battle Kukku 15th. This time, the prince has been outfitted with some snazzy combat armour, and is capable of firing both energy bolts and flame-flares from the jetpack on his back. Speedy floats around the chamber's platforms, periodically trying to fry Tails with his various munitions. Simply stay out of the way of the electric death and lob bomb after bomb at the 16th as he sails past.
There's no escape for Speedy after this confrontation; he gets consumed by an explosive fireball after taking enough damage, leaving Tails free to fly on up to the last boss.
Comics debut in SU#17