Yakkey

Yakkey is a talking key that is needed to open the door to Tubba Blubba's Heart, the invincible monster's only weakness. The key is locked away in a treasure chest in Tubba Blubba's bedroom. During the events of Paper Mario, the hero Mario had to sneak past Tubba Blubba, who was sound asleep in his bed, and open the treasure chest containing Yakkey, Unfortunately for Mario, Yakkey was a talking key and completely loyal to his master Tubba Blubba. As a result, Yakkey screams as loud as he can, causing the invincible Tubba Blubba to wake up. Mario runs away with the key, and Tubba Blubba chases the plumber through his fortress. Eventually, Mario reaches the windmill that holds Tubba Blubba's weakness, his heart. Thus Mario puts Yakkey into the lock, and turns the key...