Fury Bowser

Fury Bowser is a form that Bowser takes in the Bowser's Fury campaign of Super Mario 3D World + Bowser's Fury. In this form, Bowser becomes a gargantuan , being one of the largest physical forms he has ever taken. Similarly to Black Bowser from Paper Mario: Color Splash, Bowser becomes corrupted by black paint, which causes his skin to become entirely black in color, complete with glowing yellow eyes without pupils. In contrast, his hair glows a bright red, while the center of his carapace and the tips of his shell spikes glow yellow and red. It is implied by Bowser Jr.'s paintings, both when Mario first encounters him and in the credits, that the form was unintentionally caused by Bowser Jr. painting his father black and angering him.

In comparison to his normal self, his body is much larger than his head, his tail is somewhat longer, he has more spikes on his arm bands, and he has more defined pectoral muscles; the latter trait is shared by Bowser's appearances in the Super Smash Bros. series. Compared to Bowser's normal roar and even Dry Bowser's roar, Fury Bowser's roar is more realistic-sounding, deeper and almost demonic, and has a reverberating echo effect.

Behavior
Typically, Fury Bowser is found sleeping in the middle of Lake Lapcat, hiding his whole body inside the Fury Sun (a spiky blob of goo that resembles Bowser's Spike Ball form in Mario & Luigi: Bowser's Inside Story and the Super Mario Galaxy games, as well as the spiky shells he throws in his Super Mario Odyssey battles), which slowly rises from the ground. He usually awakens at intervals of roughly six minutes, but scanning the Bowser amiibo in the game causes him to appear instantly. His awakening is foreshadowed by the current music changing, and a small rainstorm starting. After a few moments, Fury Bowser will quickly launch into the air as the screen becomes completely white. This transition changes the clear daytime sky of Lake Lapcat to nighttime during a torrential storm.

Once awake, Fury Bowser will land at a location near Mario and begin rampaging. During his rampage, many spike-shaped platforms are launched into set locations on the different islands of Lake Lapcat. Some platforms have Mushroom Trampolines on them, and many can be used by Mario to scale platforms more quickly. Several large land masses of a similar material with Dash Panels will rise from the water, and they can be used by Plessie to move faster and cross gaps of goop. Large, gold blocks that resemble Moon Rocks and usually have ? Blocks containing coins above them also appear.

During Fury Bowser's rampage, he will target Mario with large beams of fire, which will destroy the spike-shaped platforms and gold blocks upon contact (the latter leaving behind coins). These fire beams will sweep across Lake Lapcat with a very long range, but can be avoided by hiding behind walls or the other objects spawned during the rampage. Additionally, this fire is the only thing capable of destroying Fury Blocks; to show this, the Bowser emblems on the blocks glow red during the rampage.

Throughout the rampage, meteors fall around the entirety of the lake and leave behind small circles of lava where they land, which will disappear after enough time or if Fury Bowser stops rampaging. All kittens and calico cat parents on the lake become corrupted for the duration of the rampage.

After a while, or if the player collects a Cat Shine, Fury Bowser stops attacking and goes back into his slumber. The sky will change back to calm daylight, all objects summoned during his rampage will disappear, and all Fury Cats will return to normal. If his rampage is ended by collecting a Cat Shine, a nearby lighthouse will either begin to shine or shine brighter than before, and this light damages Fury Bowser slightly. However, it is impossible to defeat Fury Bowser by only collecting Cat Shines, due to the damage stopping once he reaches one point of health.

Battle
If Mario has collected enough Cat Shines to awaken the Giga Bells, they will become active while Fury Bowser is awake, allowing Mario to obtain them. After Mario obtains a Giga Bell and becomes Giga Cat Mario, a boss battle against Fury Bowser occurs; this happens five times throughout the game.

Both Fury Bowser's behavior and the color of the sky change depending on how many time he has been defeated before. Initially, the sky is black during his rampage, which lasts for a few minutes. After he has been defeated two times, the sky changes to be slightly red, and Bowser will stay for much longer unless a Cat Shine is collected. After he has been defeated three times, the sky becomes much more red, and Bowser will no longer retreat on his own, forcing the player to collect a Cat Shine to end the rampage. The final battle with Fury Bowser is available when the player has 50 Cat Shines. Therefore, if the player has defeated Fury Bowser four times and collects 47 Cat Shines, Fury Bowser will force a rampage and cannot be sent into slumber, forcing the player to collect the remaining three Cat Shine while he is still attacking. However, if the player collects more than 50 Cat Shines before the third battle, the continuous rampage state will not occur after it.

Fury Bowser uses several different attacks during these fights. He may shoot beams of fire while moving his head back and forth which Mario must jump over to avoid damage. He can also dig into the ground to summon much larger spike-shaped platforms, which will fall onto the ground in areas denoted by flashing red markers. These platforms can be grabbed by Giga Cat Mario and thrown at Fury Bowser, which will cause him to retract into his shell and flip over. Sometimes, he will enter his shell and roll towards Mario on his side; if Giga Cat Mario claw swipes his carapace while he does this, he will also flip over. Finally, Bowser can enter his shell, jump up and aim at Mario, with a red circle appearing in the place he is set to land; once he does, a shockwave of fire emerges from him and he is flipped over. In later fights, he gains additional attacks, such as breathing a ring of huge fireballs and summoning gigantic Kick Bombs. The latter can be deflected back at him, flipping him over. His rolling and flipping jump attacks will also repeat themselves multiple times before he switches to another attack.

If Fury Bowser's shell is flipped over at any point, his carapace will temporarily become vulnerable to Ground Pounds. Doing this successfully will cause massive damage. Fury Bowser also can be claw swiped by Giga Cat Mario at any time, but this only does a small amount of damage. A red health bar is above Bowser and shows how much remaining health he has; during his first battle, it takes a total of six Ground Pounds to deplete his health bar completely. If Mario is hit by one of his attacks, he will turn into a gigantic version of Super Mario. However, the Giga Cat Bells will respawn infinitely at their shrines to allow Mario to recover health.

After enough of Fury Bowser's health bar has been depleted, he will be heavily knocked back and fall to the ground, seemingly unconscious. What happens after this depends on whether his health was fully depleted or not. If it was not, then Bowser will get back up, shake his head, and return to the Fury Sun. If Mario completely depleted his health bar, however, then he will glow brighter and brighter until a massive explosion occurs, causing him to fly upwards in his shell from the blast and hit the water before sinking back down and returning to the Fury Sun to recover. The latter outcome is the only way Fury Bowser can be defeated for his next phase to appear.

When Fury Bowser is defeated for the second, third, and fourth times, new islands to explore will rise from beneath the water. When he is defeated for the fifth time, he expels a large amount of black paint from his mouth before glowing, and is then engulfed in an even larger explosion. Bowser Jr. approaches him with caution, but he rises back up as Super Bowser, causing his son to flee. Devoid of black paint, Super Bowser traps all three Giga Bells in a large crystal ball as the final battle begins.

If Bowser's Fury is played after Super Bowser has been defeated once, Fury Bowser will be on either the first or second stage of attack, and the Giga Bells always have no black paint on them, allowing the player to fight Bowser whenever he appears. If 100% completion has been achieved by collecting all one hundred Cat Shines and then defeating Super Bowser again, the red and yellow parts of Fury Bowser are changed to a bright white, and the health bar that appears during battle changes from red to blue. He will also always start battles on maximum health, regardless of if his health has been depleted prior by collecting Cat Shines.

Trivia

 * Fury Bowser bears a resemblance to Bowser's appearance when using his Mega Strike in Mario Strikers Charged.
 * Fury Bowser and the material in his surroundings resemble, a typically dark fluid that can form spikes when influenced by a magnetic field.