Grune is every Thunderian's worst nightmare - a ThunderCat, with all the enhanced skills that go with that title, yet with a lust for power that corrupts his heart and turns him into a force for evil. In many ways Grune is the ThunderCats' most lethal enemy - an ethereal, ghostly force who cannot be harmed by physical assault, Grune attacks the ThunderCats with but one goal in mind: vengeance, against the Thunderian race in general and in particular his old friend, now an ancient enemy, the spirit form of Jaga the Wise.

Coming soon will be a list of each appearance made by this character as well as a summary of their role in this episode.