Meowser

Meowser is the name used for the Cat form of Bowser introduced in Super Mario 3D World. Bowser obtains the form only once during the final battle in The Great Tower of Bowser Land. He has white and orange fur with brown stripes, similar to a tiger's, a ringed tail, cat ears instead of horns, whiskers, and his nose is black. His hair is colored red, white, and brown, and his shell appears to become more gray-blue, looking similar to Dry Bowser's (but without red gaps). Even his trademark roar becomes different, giving off more of a meow-like sound. Additionally, he is larger than normal Bowser. Like Cat Goombas and Cat Bullet Bills, the form is more akin to a transformation than a suit. The name is a portmanteau of "Bowser" and "meow", the onomatopoeia for the sound that a cat makes.

Super Mario 3D World
Meowser appears in Super Mario 3D World where he makes his only appearancen in the game in the final section of the level The Great Tower of Bowser Land, as he uses the form in an attempt to fight the player(s). Like Cat Mario, Meowser can climb walls and swipe his claws at his enemies. Unlike Cat Mario, however, his tail is large enough to whip, like Tanooki Mario, as well as retaining his ability to breathe fire (though he uses this less often). After the the player(s) attack him with a POW Block, Meowser uses the power of Double Cherries to become Double Meowser, spawning up to five doubles to fight them. The player cannot harm Meowser directly; the only way to finish the fight is to hit the giant POW Block four times at the top of the tower to defeat Meowser. The Clear Pipe to the Goal Pole will then be revealed.

The final boss battle against Meowser is reminiscent of the final boss battle against Wario at the end of Super Mario Land 2: 6 Golden Coins, where the final boss uses power-ups against the player. It is also similar to The Adventures of Super Mario Bros. 3 episode "Super Koopa", where Bowser also uses power-ups against the Mario Bros. (though through the use of a pendant, rather than the power-ups themselves, and only in the Real World).

Super Mario Maker 2
Meowser appears as an enemy in Super Mario Maker 2, which shows him in his cat form if the player gives him the Super Bell powerup. His appearance only shows him and similar effects from the original game in the Super Mario 3D World theme.