One of my most interesting characters was a CN (read: completely and brokenly insane) Elf named Random.
As a young (relatively speaking) elf, he was walking through the woods near his family home when he accidentally stumbled into a wizard's duel due to his lack of attention. By the time he noticed what was going on, he had been struck multiple times by ongoing magical effects. The experience left him infused with magic and altered his appearance. Now having blue hair, red skin and yellow eyes, he tried to make his way in the world. The infusion of magic left him a penchant for both arcane and divine magic (Sorcerer and Favored Soul, respectively) but tapping into too much at once slowly started to break his mind further.
The breaking point:
After a while travelling, he attracted the notice of two local groups of fey. Both groups attempted to recruit this strange-looking newcomer with a mix of fey sorcery and fey nature magic. The combination shattered the division between his arcane and divine power, merging the two into an anarchic whole (Mystic Theurge PrC). As his mind completely shattered, the final fragments of sanity manifested as a familiar, a raven named Poe, and it was all that was left of Random's rational thought (Poe had both a higher Intelligence and Wisdom).
Enter: the Broken:
Random's spells and abilities all fell into mind-f#@*s and battle control, he had very few direct damage spells. His favorite tricks were using Alter Self + Mirror Image to look like one of his opponents, or Phantasmal Terrain to have people walk into/off of things. He would Suggestion/Otto's Irrisistable Dance/Tasha's Hideous Laughter the entire enemy party while his allies cleaned up. In the event he needed to fight seriously, he would cast Enlarge Person, Divine Might, and then Righteous Might/Tenser's Transformation/Body of Iron.
Suffice it to say, he drew atttention. Mortal and Immortal alike began to take notice and vie for his aid in battle and he began to inspire a cult following of the insane and cast-out. He became so unstable, that his body itself began to change at will and he became a were-tiger. His familiar, Poe, absorbed enough of the cast-off magic to take a level each in Wizard and Druid and got a Badger animal companion named Edgar. Before the gods realized what was happening (too busy trying to decide who he belonged to), enough mortals had begun to worship him that he ascended to godhood as the Mad God of Atrophy, called the Avatar of Chaos Unending. His followers seek to reduce the world back to its primordeal state. His domains are Chaos, Trickery, Destruction, and Insanity.
Suffice it to say, my DM does not allow me to play him anymore. He still shows up from time to time as an NPC and my PC characters are allowed to have him as a deity.