ECKS DEDEDE

ECKS DEDEDE is a hidden joke super-boss within the game. It is one of, if not the most difficult boss in the entire game.

It is a boss implemented for fun, and killing it will not trigger anything progression-wise.

Appearance
ECKS DEDEDE appears as a heavily pixelated image of a red star overlay-ed by a blue square. It has no face.

Fight
Every single frame, the AI that ECKS DEDEDE uses has a chance to change into another AI. All of the possible AIs it can change into are from Boss AIs. This means it can spawn minions, just like the Void Wormhole from Shift Final, or Snake Babies from Serperannus. It may even enlarge, shrink, teleport or go off-screen depending on how the AI works.

Trivia

 * ECKS DEDEDE has 3 references. One of which is to a Nintendo character (King Dedede), a popular form of text spread throughout the Internet, known as 'XD', and a removed boss from a Terraria mod called Calamity, known as THE LORDE.
 * ECKS DEDEDE's doesn't have an original theme, and there will not be one (confirmed).