Moya Triad

The Moya Triad, or the Moya Brothers, are a trio of "ninja" (though they lack the skill of even the most feeble shinobi). Aniki, the eldest brother, serves as their leader. They each have a stylised haze cloud symbol on their forehead protectors that almost resembles a question mark. They claim that they are very wealthy.

Background
Aniki holds a grudge against Kakashi Hatake for coming to the aid of a girl he had been stalking, and then leaving the trio tied up in a bundle hanging from a tree while the girl left with Kakashi.

Part I
When Team Kakashi went on a mission, the Moya Triad tried to get revenge on Kakashi, which consisted of hiccup drug in the food and laughing darts, which will make him hiccup and laugh until he dies from it, respectively. Both attempts failed horribly. The Triad were ultimately lured out unintentionally by Kakashi's three students, who wanted to unmask their teacher, but was mistaken by the Triad to be enemies of Kakashi as well. Taking advantage of this misunderstanding, the three reveal themselves with a bottle of poison that will make Kakashi cry forever to death, only to be shocked that Kakashi informed them he already knew of them stalking him all along, and had been waiting for them to come out. The rest of Team Kakashi, who had been tied up by their teacher, falsely stated that they disguised themselves with the stolen Moya ninja uniforms to lure the three brothers out, in order to cover up their own attempt to unmasking their teacher. Kakashi then advanced on the Moya Triad, and, ignoring their fearful begging for mercy, beat them up and left them tied up and hanging again on the barn house, all the while revealing that he did not remember who they are to begin with, much to their chagrin.

Konoha Hiden: The Perfect Day for a Wedding
The Moya Triad were seen disguised at Tomiya Inn. They were welcoming Shikamaru Nara and Temari to the inn alongside Okami.

Trivia

 * They also appear in Naruto: Path of the Ninja 2, and fighting them gives the most experience out of any enemy in the game.

Moya-Nin