He was playing the invisible monster; she'd seen that story in one of the comic books.

He suddenly finds himself with the same, about to feed the invisible monster.

"But I don't believe in an invisible monster either!"

I'm an invisible monster, and I'm incapable of loving anybody.

When they came to me with their few confused beliefs-were there not invisible monsters everywhere?

She didn't believe Michelle's stories about invisible monsters.

The next new serial, The Invisible Monster, followed in spring of 1950.

A radar device that Gavan uses to detect invisible monsters.

Well, I just got out of a mental institution and I'm being followed around by some kind of invisible monster.