Summons are somewhat of a useful part to the gameplay of Kingdom Hearts 2, similar to the battle use and the similar effects, the Summons are used the same as in Kingdom Hearts 1. They are effective in a tight situation, but they have as a a loss, the use of Magic. Typically, their use is mainly for fun, for those who enjoy a good 'drive.' Despite that they are useful and can be used when such times cause the need of help. To Summon a Summon creature, switch

Stitch
Obtain Location : Hollow Bastion Computer Room Hallway

After the first Space Paranoids World Visit, you can locate Stitch In Hollow Bastion. As an alien with a gun, Sitch can attack and deafeat the Heartless and Nobody's as fast as they can come. His attacks are musical and they can be deadly as well.

Chicken Little
Obtain Location : One Hundred Acre Wood

As small as they get, Chicken Little goes to Sora, and can blast enemies, using a target system once you summon him. He can run around attacking, while you bash enemies, and then get help from Chicken Little later. There is an FPS mode where you control Chicken Little and shoot enemies in FPS format.

Genie
Obtain Location : Argrabah (After Volcano and Blizzard Lord)

Returning Once again as a Summon to help Sora on his journey again, Genie wields a 'keyblade' of sorts to help in Battle, Genie can attack with his improvised keyblade to heartless, or the enemy ahead, or even use Magic to decimate heards of Heartless to aid you in the oncomming Unslaught.

Peter Pan
Obtain Location : Port Royal

Replacing Tinkerbell since the first Kingdom Hearts, Peter Pan can allow Sora to fly, as well as to use his abilites to attack, and defeat the heartless. Tinkerbell Joins him and while the summon continues, Tinkerbell will heal Sora and Peter Pan.