Dareth

 Dareth was a character in the LEGO Ninjago: Masters of Spinjitzu TV show.  He owned a place called the "Mojo Dojo", which is where the ninja train.  He tried to join the ninja team by dress in brown ninja gear and called himself "The Brown Ninja", but it didn't work, but after putting on the helmet that allows you to control the Stone Army, he saved the ninja and became part of the team.

LEGO Ninjago: Masters of Spinjitzu

Name:  "Grand Sensei" Dareth or "The Brown Ninja"
Years:  2012

Appearances:
LEGO Ninjago: Masters of Spinjitzu
  Season 2:
    •"Pirates vs. Ninja"
    •"Ninjaball Run"
    •"The Day Ninjago Stood Still"
    •"The Last Voyage"
    •"Return of the Overlord"
    •"The Ultimate Spinjitzu Master"