Phantomtail

The Phantomtail is an Emblem Heartless that is found in Kingdom Hearts 358/2 Days. It is one of the bosses at Neverland.

Kingdom Hearts 358/2 Days
Roxas discovers Captain Hook and Mr. Smee taking a captive Tinker Bell back to their ship. He follows them, and learns that Hook has been following fake treasure maps in the hopes of finding a real one among them. Hook tears up one of the fakes, and he and Smee leave the ship to continue their hunt. Roxas frees Tinker Bell, and follows one of the pieces of the torn map, expecting to find a Heartless. When no Heartless appears, he tracks down Hook and Smee, who are digging up another chest. Hook's greed ends up summoning a Phantomtail. Roxas slays this monster, and returns to the Castle That Never Was. After he leaves, Pete comes by the dig site, wondering what happened to the Heartless he had expected Hook to attract. He realizes someone is destroying the Heartless, and plans to summon an enormous Heartless.

Strategy
At the start of the battle, Lock-On to the Phantomtail's wings or tail as it hovers above you. As this is an aerial battle, you must jump to the Heartless' level before you can begin your attack. Use caution, as the Boss will eventually proceed to summon homing balls of blue energy to damage you. From this point forward, the Heartless will warp around the battlefield, making attacks difficult to land.

You must also be careful not to get too close to the Phantomtail, as it will stab you with its talons in an attempt to knock you away. Another attack in this Heartless Boss's arsenal involves it spiraling into you, dealing impact damage. The Phantomtail will also flip in the air, damaging those in its way. So long as you heal periodically, utilize your Limit Break, and attack whenever possible while at the same time dodge the beast's attacks to the best of your ability, you should be able to tackle the Phantomtail in a matter of minutes. If you wish to use Magic in this battle, use the when the Heartless is stationary. Attempt a spell while the beast warps to a new location, and your spell is guaranteed to miss.