Yoda's Ghost is a playable character in Lego Star Wars II: The Original Trilogy. He is made available for purchase when all story modes are cleared. Yoda's Ghost costs 1,200,000 lego studs to purchase, and is the most expensive character in-game.
Yoda Died of natural causes on the planet Dagobah in his house at the age of 900, after telling Luke vaugely about another family member. He then finally became one with the force and appeared to Luke as a ghost along with fellow deceased Jedi Anakin Skywalker and Obi-wan Kenobi.
Yoda's Ghost moves exactly the same as he did when alive, and is controlled the same, but is completely invulnerable to attack and invincible to all enemies.