Master Sifo-Dyas
I big mystery in the Star Wars world. How did he die? Who gave him permission to create an entire clone army for the Republic? Will this mystery be unraveled in the upcoming Star Wars television series of 2007 (Untitled, live-action TV show set betweeen episodes III and IV)? I do know one thing. Master Sifo-Dyas was one of the 'Background Jedi' of The Phantom Menace.
So,
1. He was seen in Episode I (Kaminoan Jedi)
2. He is a Kaminoan.
3. He was killed. Not death by natural causes, definately killed.