Tubba Blubba

"I smell delicious ghosts! Open the door!"

- Tubba Blubba

Tubba Blubba is a giant, blue-colored Spike with a spiked shell. He is a follower of Bowser who, despite his fearsome appearance, is actually very sensitive, frail, and cowardly. His nickname is "The Invincible Tubba Blubba", although he actually does have a weak point: his heart (similar to Sluggy the Unshaven of Super Mario World 2: Yoshi's Island). Tubba Blubba's name is a corruption of "tub of blubber" (indicating obesity).

Paper Mario
Lady Bow mentions that the Boo inhabitants of Boo's Mansion and Gusty Gulch used to enjoy scaring Tubba Blubba. However, 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, and appointed him as guard of the Star Spirit Skolar. No longer frightened by Boos, Tubba Blubba began steadily devouring all Boos he came across, avenging them and ironically making them scared of him.

Mario arrives at Gusty Gulch right before one of Tubba Blubba's Boo-devouring excursions. Tubba Blubba does not notice Mario due to him using Lady Bow's Outta Sight technique to turn invisible. Later, when Mario sneaks into Tubba Blubba's bedroom to find out his weakness, he is awoken by Yakkey, an anthropomorphic key which unlocks the door to the Windy Mill, the storage place of Tubba Blubba's heart. Tubba Blubba chases Mario through the castle, but his progress is impeded by a group of Boos holding the castle doors shut.

Tubba Blubba breaks through this barrier while Mario is engaged in combat with his sentient heart. Upon its defeat, it flees from Mario and rejoins with its body, which makes Tubba Blubba feel invincible but actually physically weakens him. After his defeat, he reveals that he is actually quite sensitive and begs for forgiveness before releasing all of the Boos he had consumed. He then retreats, claiming that he does not want to be invincible if it means fighting people like Mario. He is not seen again until the game's ending parade, during which three Boos give him a ride through the air while his heart chases after him.

Super Paper Mario
In Super Paper Mario, Tubba Blubba 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.

Mario Golf: Toadstool Tour
Tubba Blubba's name sometimes appears on the score card in Mario Golf: Toadstool Tour.

Characteristics
Tubba Blubba shows weakness after being defeated by Mario and his allies, attempting to hold back tears and running back to his castle. He appears reserved, spending much of his time sleeping and nourishing himself on a diet of Boos. His castle is poorly maintained, with visible cobwebs in its corners, cracks in the walls and ceilings, and during his pursuit of Mario, a collapsed bridge that connected the hallways to his room and the stairway. He apparently employs or is in command of several Clubbas who, like him, enjoy dozing off into slumber when they aren't active. Tubba Blubba also has several Sentinels patrolling the hallways. It is unknown if these were given to Tubba Blubba by Bowser or if they exist in the castle to ease Tubba Blubba's fear.

Tubba Blubba apparently feels more powerful when separated from his heart, who controls him from a cave. Despite his new abilities, Tubba Blubba is still afraid of Bowser, and worries about upsetting him. With his heart, and according to several Boos in the game, he is very cowardly and sensitive.

Trivia

 * There is a similarity between Tubba Blubba and Grubba. Both of them look similar to each other, both have blue skin color, and both are Chapter 3 bosses. Both of their English names are based on Clubbas rather than Spikes, although neither of them are club-wielding soldiers. Also, both have spikes on their shell. Lastly, they both have a well-guarded secret to their "invincibility".