The Nobodies are a new sort of enemy that appear in Kingdom Hearts II. They resemble the Heartless in the sense that there are different types and they have a symbol, etc. They are created when someone with a strong heart leaves their body and soul behind when they lose their heart to the Heartless. The Organization are Nobodies of people that had very strong hearts, so they retained human forum with few changes.
 Types of Nobodies
A mild threat, they can annoy you when they sink into the floor, invulnerable to attack. (similar to Shadow/Neoshadow Heartless) If they are left alone for a while they will self-destruct causing good damage and stealing some experience from Sora.
Related ThreadsHeartless, Nobodies, what next?***SPOILER!*** - last post by @ Apr 17, 2006
Nobodys? who could these creatures be? - last post by @ Apr 9, 2006
Make Your Own Heartless or Nobody - last post by @ Apr 15, 2006
Hey, if nobodies don't have feeling then..... - last post by @ Jun 8, 2006
Heartless and Nobody Speculation - last post by @ Apr 2, 2008