Konoha has a sub-division of Anbu known as "Root" lead by Danzō. Danzō created "Root," a secret group within the Leaf village that swore to do what the dove-like Hiruzen could not. Root would take orphans and rob them of their names and emotions, leaving only soulless assassins capable of carrying out any order. But Hiruzen found out and had the group disbanded, however the group continued on in secret.
Anbu wear animal masks to distinguish themselves from other shinobi and to hide their faces to keep there identities completely hidden.
The males have a signature tattoo on the left shoulder and the woman have them on the right (To determine gender between the members.)
They wear black and grey armor that has arm guards and a chest plate for protection.The Anbu have also been know to wear large cloaks in plain black over there armor and squad leaders tend to wear white cloaks. And they wear animal masks.