Sharingan Spying Creature

Shin Uchiha employed several of these creatures as a means of spying on others and remotely communicating with his clones. They have an askew mouth, a humanoid nose, four small limbs, a tail, and a single large eye featuring a fully matured Sharingan. As they seem to share Shin's skin color and features it can be assumed that they were somehow cultivated from his DNA, though their origins are never explained.

Abilities
The creatures are highly stealthy, capable of spying at the gate of Konohagakure without being detected. While it is unclear whether the creatures possess a consciousness of their own, Shin was able to remotely control their actions and speak through them, and he and his clones also shared their vision with the creatures. With his right Sharingan, Shin could utilise a space–time ninjutsu to transport himself to the creatures' locations, and he could activate the technique through the creatures' own Sharingan to return to his hideout. The creatures' eyes could also take on the appearance of Shin's Mangekyō Sharingan, and in the anime, he demonstrated the ability to activate his object manipulation technique using a creature's Mangekyō.

Sarada Uchiha Arc
Shin had one the creatures stationed outside Konohagakure, which allowed him to observe Sarada Uchiha leaving the village. He then sent one of his clone sons to capture her, but when the Seventh Hokage interfered in the kidnapping, Shin used the creature to transport his son back to his location.

Shin later used a second creature to transport himself and one of his sons to Ridge Tower, where they again assaulted Sarada and her companions. When they were defeated by her friends and family, Shin had the creature teleport himself and his son back once more, while also taking Sakura Uchiha so that she could treat his injuries. When their hideout was later attacked and Shin's sons betrayed him, he attempted to have one of the creatures teleport Sakura and Sarada away with him, but the latter intercepted the creature and punched it in the eye, seemingly killing it.

Trivia

 * In the manga, Shin appears to have at least four of these creatures in his service, and they can be distinguished by their nose being on different sides of their face. In the anime, only a single creature is seen, with its nose always on the right side.
 * In the anime, Orochimaru appears to have one in his possession growing within a tank.
 * Loot Crate released an exclusive licensed plush toy of the creature in its June 2019 Loot Anime subscription box, giving it the name "Sharingan Creature" — the only time it has been officially named.