Viper also known as Matthew Robinson is a minor antagonist who first appears in a new episode "SideSnake" and video game KND: Undercover 2: The Wally Begins. He is a evil explorer with snake-like appearances and most poisonous villain in the world. He will be voiced by a Tom Kenny.
- He is sneaky, evil, scary and poisonous.
- He is tall and very slender, have light skin, brown hair, yellow eyeballs with brown iris, scar on his cheek, sharp nose, forked tongue, fangs (hence his name) and wears british pith helmet, green necktie, tan coat, shirt, monocle, black pants and boots.
- He is a playable character. To unlock him, smash the four vipers.