F

is a Kumogakure shinobi.

Appearance
F has short spiky hair and a small goatee and wore the standard uniform of Kumogakure shinobi along with the forehead protector.

Shinobi World War Arc
During the Fourth Shinobi World War, F was attacked by a White Zetsu clone on the battlefield. He was later impersonated by this Zetsu and along with a group of other transformed clones, were confronted by Naruto and B on the battlefield, while B told F that they needed to protect the headquarters but Naruto immediately attacks him, revealing that he is a clone. It is unknown if the real F is alive.