A.R.R.O.G.A.N.T.

A.R.R.O.G.A.N.T. (Absolute Rumbling Rogue Omnipotent God of Amazement and Notorious Talent) is a final boss. It is considered by itself to be impossible to beat, and anyone standing in its path shall be obliterated. As such, it never appears before round 255 in any challenges. It has not 5, not 10, but an amazing two stages! Nothing stands a chance against it.

First stage
Health: 1

Speed: 0.001

Hitbox: 1024px

Abilities: Firestorm, Shield

Dialogue: (upon spawn) ''MWAHAHAHAHAHAHA! YOU CAN'T STOP ME!''

The first stage has A.R.R.O.G.A.N.T. sporting a bright, fiery look. It is resistant against all damage dealt from door handles. Its abilities are devastating. Firestorm deals a whopping 0 damage to towers it hits and has infinite penetration. If this hasn't taken you down, Shield will put nails in your coffin. This ability will put a shield around your towers, making it impossible for bloons to attack them. These two activities are what makes the first stage so terrifying.

Second stage
Health: 1

Speed: 0.01

Hitbox: 768

Abilities: Poison cloud, Stun, Terror

Dialogue: (upon defeating first stage) ''HOW DARE YOU! I SHALL MAKE YOU PAY!''

In the second stage, A.R.R.O.G.A.N.T. has a clownish look. This is an extremely effective intimidation tactic. Its speed increases significantly, due to its smaller hitbox. The abilities here are even more damaging than the first stage. A.R.R.O.G.A.N.T. can release a Poison cloud, which expands and deals 0 damage per second to any unfortunate towers trapped inside. Stun summons a bolt of lightning on itself, rendering itself useless for 2 seconds. Terror flashes a picture of its 5-year-old doodle on screen, scaring, and thus demoralising, the player. With all these abilities, it is virtually impossible to beat.

Defeat
Upon defeat, the message "MY CHILDREN WILL GIVE YOU A TASTE OF DEFEAT!" will flash on screen. Then, it releases 2 regen reds.

Trivia

 * So far, no strategies have been discovered that can even stand against the first stage. If you find any, remember to put them in the comments.