Baku

The was a personal summon of Danzō. It is a gigantic elephantine chimera that has a powerful suction from its mouth. According to Madara Uchiha, it is a legendary beast that eats dreams and nightmare, and was much bigger than he expected. Danzō took advantage of the suction to increase his Wind Release: Vacuum Serial Waves. However, the suction makes it weak against fire-based techniques, as Sasuke Uchiha took advantage and launched a fireball into its mouth, causing it to disappear.

Trivia

 * A is also a mythological Japanese creature said to eat dreams and nightmares. As a chimera with an elephant's trunk, a rhinoceros' eyes, an ox's tail, and a tiger's paws, they resembled somewhat the real-life Tapir. After the two creatures were connected, the Baku was more and more often depicted as a tapir. Modern images depicting Baku as actual chimera are rare.