Shadow Sensei

The Shadow Sensei (or the Master of Shadows) is a mysterious penguin that leads the Shadow Ninjas. Little is known about him. Like all Shadow Ninjas, he wears a special shadow ninja cloak suit. He also has a beard and wears a cone-shaped hat.

Background
It's unknown where Shadow Sensei is from, or who his relatives or friends are.

Trivia

 * The only ones who know about Shadow Sensei are the Shadow Ninjas.
 * Shadow Sensei rarely leaves the Shadow Hideout. When he does, he activates his ninja stealth mode, enabling him to turn completely invisible.