Fury Bowser
The title of this article is official, but it comes from a non-English source. If an acceptable English source is found, then the article should be moved to its appropriate title.
God Slayer Bowser is a form that Bowser takes in Super Mario 3D World + Bowser's Fury. In this form, Bowser becomes gargantuan, being one of the largest physical forms he has ever taken (along with Giant Bowser). Similar to Black Bowser from Paper Mario: Color Splash, Bowser's skin becomes entirely a black color with glowing yellow eyes without pupils, though in contrast, his hair glows a bright red and the tips of his shell spikes glow yellow and red. In comparision to his normal self, his body is much larger than his head. He also noticeably has larger abs. God Slayer Bowser has amplified versions of his fire breath attacks. He can rain meteors across entire islands, and breathe long strings of fire at his targets.
He is seen terrorizing an island filled with cat-like characters, and Mario, with assistance from Bowser Jr. works to take down God Slayer Bowser by using the power of the giant Super Bell.