Mr. Goodbye

Mr. Goodbye is a secret monster in the game. To access him, you have to find the secret entrance to Mr. Goodbye's area, The Under-Void, and parkour up the side of a wall. Then you can fight Mr. Goodbye.

Appearance
Mr. Goodbye appears to be a red-tinted Rock Monster with glowing, red eyes.

Trivia

 * Mr. Goodbye has the most health out of any monster, at a whopping 1 trillion.
 * Mr. Goodbye deals the most damage out of any monster, at also 1 trillion.
 * The name "Mr. Goodbye" is a reference to his insane stats and how he is borderline impossible to beat.
 * Mr. Goodbye has been confirmed to move 4x as fast as the player, considering his jittery movement.
 * Mr. Goodbye doesn't give any Experience when he is defeated.
 * In the lore of the game, Mr. Goodbye is theorized to be the "mysterious entity taking over the universe, destined to destroy it." It is actually the "distraction" the Guardian of Yang created for The Hypertitan.

Drops
Mr. Goodbye, if somehow defeated, will drop Corrupted Essence. This item does not do anything, and is purely for show.

How to Kill
Due to Mr. Goodbye's ridiculous stats, attempting to beat him is a ludicrous thought. There are a few ways to make beating him just a little easier though.

One way is to use a barrier (such as the entrance of an area) and go behind it, in which Mr. Goodbye cannot access. You can then hit him indefinitely and he will not be able to do any damage to you. For this way, you do not have to run around trying to avoid Mr. Goodbye.