Monkey on Their Backs

Monkey On Their Backs
This was an anti-heroin PSA created in the early 70s that has a screamer at the end. It first shows a wind-up monkey crashing its cymbals as a little girl's voice says, "They say that people on heroin had a monkey on their back. Isn't it cute?". Suddenly, the wind-up monkey stops as the camera zooms in to the monkey's face, which switched to a still of a real screaming monkey with a loud primate scream. It is widely-known to be one of the first, if not the first, screamer in the world.

Links
NOTE : The following video contains a screamer.
 * youtube.com/watch?v=AegsJYtwccw