I created the character intending just to do the Shivering Isles expansion (I've not played through the questlines there) then retire him, but ended up working out a backstory for him anyway, so I think he's going to become a permanent fixture.
There will be Shivering Isles spoilers along the way as he undertakes quests- just a warning.
Name- http://i1122.photobucket.com/albums/l528/Lady-Mara-2/Mynthel.jpg
Race- Wood Elf (male)
Story- Mynthel was raised by goblins after being snatched as a baby. He has spent most of his life in a cave and has seen sunlight only a few times, hence his unusual appearance. (The picture doesn't show it very well but his hair is white.) Most of his life he has been haunted by dreams of butterflies and colourful skies. These butterflies started talking to him in his dreams, telling him to do things, and he went insane, murdering his goblin shaman and mounting his head on a staff. He escaped the cave and followed the butterflies to a strange doorway in the Niben bay, where he entered the Shivering Isles without a second thought. He became mesmerised by the plants and skies and wants to see more of this colourful world.