The Hunger

The Hunger, also known as John, is a former spokesperson turned sentient plane. It feeds on other planes, and also serves as the endgame, main antagonist of the Balance Arc campaign.

The Stolen Century
The Hunger is first encountered by the Red Robes as they are leaving their home planet. It starts attacking and feeding on their plane, forcing them to escape.

Cycle One
It later manages to find them again in another plane, and it starts to attack and devour that plane as well. The Red Robes then watch as it grows slightly bigger from devouring the plane and its Light of Creation.

John
Merle would eventually find a way to converse with the Hunger directly, and he would find it to be, in fact, a man named John. He has a slight build, looks to be in his early fifties, has salt-and-pepper hair, and wears a suit, tie, and some very nice shoes. The broad strokes of John's backstory are revealed here: John was a philosopher and spokesperson who came to realize the limitations of being mortal after pondering eternity, and came to believe that "living is horrible." He shared his dissatisfaction and fury with the people of his home plane, and soon everyone and even every thing came to agree with his worldview. It turned them into the Hunger, a force seeking to transcend existence regardless of the cost by chasing the Light of Creation, which allows the Hunger to exist and consume bonds for power.

John is now the Hunger, but it's likely he doesn't exactly know what he's doing, since he didn't even know what the Starblaster looks like or how the Light was getting away from him every cycle before Merle told him. He also said he must look beautiful from Merle's perspective, which would seem to mean that, physically, he doesn't realize that the Hunger is more terrifying than beautiful, and that, metaphorically, his mission to transcend existence, in practice, isn't as magnificent and admirable as he considers it.

Planes Devoured
All known planes that have been devoured by The Hunger.
 * The Red Robes' plane
 * The Animal Kingdom
 * The Voidfish's plane
 * The (K)nights plane

Trivia

 * The Hunger's appearance was inspired by black opal.
 * Lucretia came up with the name "The Hunger".
 * Even though Griffin chose the name "John", he does not want this to discourage people from drawing him like Jon Arbuckle, creating hilarious parallels between the big bad of the entire campaign and the mysterious Garfield the Deals Warlock.
 * The Hunger bears some resemblance to The Blob from Car Boys.