Yoda

Yoda was a powerful Jedi Master who existed during the events of the Clone Wars. He was a senior member of the Jedi council and played a pivotal role in the survival of the Jedi Order. He lived for 900 years, and he died on Dagobah, after instructing Luke Skywalker in the ways of the Force and revealing that Leia was Luke's twin sister. The information he passed on to Luke proved very important as Luke succeeded in overthrowing the Emperor and Darth Vader. After Yoda died, he managed to retain his identity and become a ghost, as had Obi-Wan Kenobi. In this form, Yoda continued to guide the Jedi for a short period of time.