Baku

The was a personal summon of Danzō. It is a gigantic elephantine chimera with tiger-like limbs and bandages wrapped all around its head, and has a powerful suction from its mouth. According to Madara Uchiha, it is a tapir that eats dreams and nightmares, and was much bigger than he expected. Danzō summoned it to battle against Sasuke Uchiha, but it was forced to disappear when Sasuke launched a fireball into its mouth.

Abilities
Called the "Nightmare Eater", the Baku is said in legend to be able to devour dreams and nightmares. When it opens its mouth, it can create a powerful suction that sucks in everything within a fairly large radius. Danzō attempted to use it to draw in Sasuke's Susanoo and its surroundings into the Baku's mouth. Danzō also took advantage of the suction to increase the power of his multiple vacuum blades. However, the suction makes the creature vulnerable against fire-based techniques. When Sasuke launched a fireball into its mouth, the size and power of the fire had increased due to the wind created from the Baku's suction.

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.