Gyoken summons a special cat from Nekogakure (猫隠れの里, "Village Hidden by Cats"), and hides inside its stomach.
The cat is able to leap on high trees due to it's agility and is extremely flexible. The cat is great at infiltration and tracking as its movement is silent and has an amazing sense of smell. The stomach of the cat also has a special barrier that obstructs chakra, protecting Gyoken from detection-type ninjutsu.