In Kingdom Hearts and Kingdom Hearts: Chain Of Memories, and now this game, you were able to use summons to help you out in battle. They were called much in the same way as in Final Fantasy X. Each summon has different powers that help out in different situations.
 Chicken Little
From the movie Chicken Little. When you summon him, you can go into FPS mode and shoot eggs at your enemies.
From the movie Aladdin in which he was the genie of the lamp until he was freed by Aladdin. He was a summon in the original Kingdom Hearts, and is back again. Here, you change Genie into all of the drive forms you have unlocked, and in each form he does a different attack that does great damage to your enemies.
 Peter Pan
From the movies Peter Pan - he inhabits Neverland, as everyone knows. He was the one who taught Sora how to fly in Kingdom Hearts. When you summon Peter Pan, you can use his powerful attack, "Neverland", in which you press Triangle to attack your enemies.
From the movie and T.V. show Lilo and Stitch. A psychotic little alien, he is featured as shooting enemies and playing guitar as a summon. When he is summoned he crawls around the screen, blocking any attacks with his gun. He rarely uses his ukulele to stun enemies and make them drop orbs and when your HP/MP is low. Sometimes he licks the gauges completely restoring them.
He has a limit command called "Ohana", in which you press X to shoot your enemies, press Square to use your Keyblade as a Ukulele and get health orbs, and press Triangle for you and Stitch to do the other two actions at the same time.
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