Shukaku of the Desert.

Spoiler:

Shukaku was currently curled up in a ball deep within the center of the Cactus Forest happily snoozing away underneath the numerous sand dunes which made up the Land of Anguish. He was completely hidden other than the subtle rising and falling of the sand which he slept under however due to his size one would normally attribute that to the sun playing tricks on their body. He was the first to arrive back in this land having conversed with his brethren and formed a joint alliance of Bijuu under the original one..the Juubi. Shinobi had long since forgotten the power of the Bijuu as they had disappeared after the events of the world war in order to regain their strength, the creation of the Juubi from their Yin chakra weakened them significantly and only recently have they been brought back to the pinnacle of their power. Shukaku in particular was having a wonderful dream about the countless Jinchuriki who had trapped him and how he was killing them in agonizing ways.