Tubba Blubba

"I smell delicious ghosts! Open the door!"

- Tubba Blubba

Tubba Blubba is a monstrous Clubba and follower of Bowser; despite his fearsome appearance, Tubba Blubba is actually somewhat sensitive and timid, and is also mentioned as having cowardice.

Paper Mario
In Paper Mario, it is mentioned by Lady Bow that Tubba Blubba was continually scared and bullied by the Boo inhabitants of Boo's Mansion and Gusty Gulch, who took great delight in frightening the timid Tubba Blubba. When Bowser obtained the Star Rod and imprisoned the Star Spirits, he made Tubba Blubba completely invulnerable by removing his heart from his body, apparently leaving a crudely stitched patch where it once was.

Now incapable of being harmed and no longer frightened by Boos, Tubba Blubba went about taking vengeance upon them for their years of torment against him, steadily devouring all Boos he came across, ironically making the Boos scared of him. Several attempts were made by brave Boos to discover some way to pierce Tubba Blubba's seemingly impenetrable defenses; most often, these Boos never returned from Tubba Blubba's Castle, but the rare few that did escape and learned at least a partial amount of Tubba Blubba's secret weakness were often tracked by the ghost devourer and eaten before they could reveal too much. Tubba Blubba's habit of devouring Boos and inability to be injured soon caused him to gain a sinister reputation, with even Bowser's own troops beginning to show fear of Tubba Blubba's might.

Charged with guarding the captured Star Spirit Skolar, Tubba Blubba failed in this duty, as, after some time of being confined by Tubba Blubba, Skolar managed to escape his keeper's castle, only to become lost in Forever Forest and captured by Boos. Lady Bow, wanting to rid her people of Tubba Blubba's menace, made a deal with Mario: In exchange for helping her find Tubba Blubba's weakness (as well as defeating him and letting her tag along in doing so), she would give him the captive Skolar, a deal which Mario accepted.

After several close encounters with Tubba Blubba both in Gusty Gulch and the being's own castle, Mario discovered Yakkey, a talking key in Tubba Blubba's bedroom. As Tubba Blubba slept nearby, Yakkey, not wanting to be taken by Mario to the Windy Mill (where Tubba Blubba's weakness lay), tried to wake his master, and succeeded. After destroying a large portion of his own castle, Tubba Blubba gave chase to Mario, who managed to escape his pursuer's fortress. As Mario rushed through Gusty Gulch to the Windy Mill, several Boos attempted to hold Tubba Blubba back to buy Mario some time (apparently, as Goombario theorized, more so for their love of Bow than a will to help Mario).

After defeating Tubba Blubba's sentient and mobile heart, which controlled Tubba Blubba's body and was his one vulnerable part, in the bowels of the Windy Mill, Mario gave chase to the organ when it tried to flee from him. Before Mario could catch it, Tubba Blubba's Heart found its body and allowed itself to be swallowed by it, making Tubba Blubba whole once more; ironically, after becoming whole again, Tubba Blubba became weaker and vulnerable, despite claiming to feel unstoppable.

Once defeated by Mario, Tubba Blubba, with tears in his eyes, will reveal he is actually quite sensitive and begin to beg for forgiveness, releasing all the Boos who he ate before running away, claiming he doesn't want to be invincible if he had to fight people like Mario.

During the ending parade of Paper Mario, Tubba Blubba and the Boos seemed to have become friends. Three Boos are shown to give the joyous Tubba Blubba a ride through the air during the parade. Meanwhile, Tubba Blubba's Heart frantically chases after its body.

Super Paper Mario
By the time of Super Paper Mario, it appears that Tubba Blubba had begun a career in television. He is mentioned as being the star of an anime based on him known as The Blubbening; it has run for at least three seasons. The Blubbening involves a princess and robots, and also happens to be a favorite show of Francis.

Trivia

 * Tubba Blubba's name is a corruption of "tub of blubber" (indicating obesity) written in the style of the Clubba species's name.
 * It is never revealed as to whether Tubba Blubba's Heart had life all along or whether its living, sentient qualities were the result of exposure to the Star Rod.
 * Tubba Blubba can be thought of as somewhat similar to Sluggy the Unshaven of Super Mario World 2: Yoshi's Island, another character who was stated in-game to be invincible while actually having a weakness in the form of his heart. However Sluggy's heart wasn't outside his body like Tubba Blubba's heart, but just protected by his gelatinous body.
 * The Stone Spike enemies from New Super Mario Bros. Wii have a color scheme that resembles Tubba Blubba's.
 * Tubba's moves share similar names of moves from the Pokémon series, Body Slam and Mega Punch.