There was nothing more frightening to me, as a child, than the soul sucking gaping faces of the Yip Yips. Of all the weird media moments in my youth, these Sesame Street aliens take the creepy-holy-mother-of-god-get-out-of-my-head cake. Their evil vacuous mouths graced TV screens everywhere in 1971 in this telephone sketch. I dare you to watch one of the clips after the jump and not feel incredibly uncomfortable or creeped out.

Especially when they start moving their mouths back and forth.

Yip Yip Aliens Discover A Radio:

Yip Yip Aliens Meet A Clock:

Yip Yip And The Computer:

Yip Yips Family Song: