10 Horror Movie Robots That Scared Us Out Of Our Minds

When one hears the words "killer robot," it tends to drum up images of a hulking android or a colossal supercomputer. But as Phantasm proves, the scariest and most efficient murder machines don't have to be much bigger than a tennis ball.

In this cult-classic, a teenager called Mike discovers an extradimensional entity called The Tall Man is preparing a global invasion. Even though Angus Scrimm is suitably ghoulish as The Tall Man, it's his Sentinels that leave our blood well and truly curdled.

At The Tall Man's command, one of these floating spheres will launch at its target, lodging itself into their head. It will then drill a hole through the skull before sucking their victim's brain juice out. Even though the Sentinels look like nothing special, they are utterly petrifying, since their victims are guaranteed a slow and unbearable death.

Despite playing a small part in Phantasm, there's no question the circular drones are the most memorable aspect of the film, as well as the whole franchise. In fact, the Sentinels became so iconic, they were reincorporated into every single Phantasm sequel.