Circus

The Circus is the final boss of the Ratboy's Nightmare Update For Fantastic Frontier, introduced in the Nightmare Boss Update. The boss can be found in the 'CIRCUS' phase of the Ratboy's Nightmare Dungeon instance, a place where players can team up with each other in order to face various obstacles and challenges that the instance offers.

For more insights on what is rewarded, check the article "Nightmare Rewards." For more information about how its HP scales, here is the formula:
 * It is based on the number of players (N) fighting: HP = (BaseHP * (N * 0.8)). So one player = BaseHP * 0.8, Two = BaseHP * 1.6, Three = BaseHP * 2.4, etc.

Appearance
The Circus is a gigantic, black, rat-reptilian, hybrid-based monstrosity with four arms. Two of which are giant, skeleton-like arms with hands that have red eyes on them that stick out of its back; the other two are tiny rat arms located near its chest. It also possesses a long, curly, rat-like tail and gigantic reptilian-like feet. Its head has a creepy, smiling face with two curved, black horns extending outwards from its head. It is claimed to be the physical manifestation of the Nightmare itself- the Nightmare's "crux" and "miscreant".

Attacks

 * Bash - The Circus will attempt to bash the player(s) into the ground, dealing hefty amounts of damage to those close to the boss.
 * Charge - The Circus will begin to charge recklessly around the battlefield, flicking players to random spots of the battlefield caught within its path. Deals moderate damage if the player(s) do not react quickly in time.
 * Horrid Reflection - If the players are close to the boss, the Circus will bend down and create a large explosive blast from its face. This is sometimes confused with the Nightmare Beams, as it may or may not appear to be a laser-beam to others.
 * Nightmare Beams - Stretches out both of its skeleton-like arms in an attempt to cast two massive beams of nightmarish energies in a fixed direction, which repeats twice more at different heights.
 * Nightmare Blast - Charges a ball of nightmarish energies mid-fight in an attempt to create a large explosive blast, inflicting heavy damage to anyone in mid-air.
 * Nightmare Chainball - Spawns a ball of nightmarish energies that will attach a chain of nightmarish energies linking to nearby players' torsos, slowly inflicting damage to affected players in order to slowly regenerate the boss' HP.
 * Nightmarish Upheaval - Circus raises its arms summoning several red spots on the ground, warning players to move before being obliterated by a pillar of nightmarish energies. Players are given 2-4 seconds to move away from the marks.
 * Quake - Slams one of its hands into the ground while casting a ball of nightmarish energies to shake the ground, inflicting moderate damage to anyone within close proximity.
 * Summon - The Circus will summon a Hand of the Nightmare to the battlefield, distracting players in an attempt to delay the inevitable.
 * Swipes - Three variants of the swipes exist; swiping with its left skeletal arm, swiping with its right skeletal arm, and swiping with both skeletal arms.

Strategy/Tips
It is highly advised for players to fight in a group in order to quickly defeat Circus. The cheesiest method to defeat the Circus is by using the Head Baiter method, where the player(s) stand on top of its head to avoid damage from most of its attacks. Players using this method should take into consideration that they are still vulnerable to any attacks of the Circus. Tips to avoid certain attacks can be seen below:
 * Bash, Charge, Nightmare Beams, Quake, and Swipes can be avoided by keeping a safe distance between you and the boss and/or by standing on top of its head to avoid damage.
 * Players should move away from red spots (markings) while the Circus is casting Nightmarish Upheaval.
 * If the Nightmare Chainball is summoned, quickly inflict damage towards the ball to prevent affected players from losing HP.
 * If the Circus summons a Hand of the Nightmare, a few players should eliminate the distraction while the other players are distracting the boss.
 * If Nightmare Blast is being charged, stay on the ground to avoid damage in mid-air.

Trivia

 * Similar to the enemies' HP scaling feature, the boss' HP can vary depending on the number of players fighting the boss.
 * The boss cannot be killed by the players, but it can be defeated.
 * Defeating the boss (once it reaches 1/7th of its HP) will load the screen that displays, "Thanks for playing!", rewarding the players up to 3 items. This is similar to the screen that loads when the player(s) defeat Mr.58 in the Otherworld Tower dungeon.
 * A cutscene will be initiated, showing Ratboy with a Ratboy Handgun to finish the Circus off. The players can be seen behind the Ratboy as he is charging up his attack.