The real horror begins when Vincent Price listen a weak and distressed voice that shouts "help! help!" and we see al last the fly in a spiderweb with the scientist head. IS TERRIFYING!

Donald Shuterland and Brooke Adams walk slowly on the street trying to imitate the invaders in the invasion of the body snatchers when, suddenly, walking through the crowd, approaches what seems to be a dog. The more he come near the more we realize of the terrible evidence. Is the homeless dog with his owner head! and besides sounds anticlimactic banjo music...

A couple of curiosities: In two Halloween Simpsons specials is done a homer, er... homage, sorry, to those films, and in one of the Nightmare on Elm Street films (I don't remember which one) appear two dogs with Freddy Krueger's head.

In this illustration I've used deep of field to emphasize even more the claustrophobic sensation that produce to the character being trapped into a strange body. Only the head is focused because it's the only human feature left in the hopeless creature. As almost every monster, he is distressed and this sensation can be clearly appreciated in his expression.