We see a woman taking a shower but only from the shoulders up above the shower door (no cleavage). You can barely see her shape through the foggy door. She steps out of the shower wearing a towel that reveals most of her legs and minor cleavage, and then walks out of the bathroom where she is surprised by a man waiting for her. She rushes back into the bathroom and comes out wearing a full modest bathrobe.

Several kisses.

Several people are killed by invisible (and visible, but late in the film) monsters.

Several monsters are killed by bullets (and an axe).

A fight between two men.

Most of the violence (at least near the end of the film) is quite graphic, especially for the time.

One instance of mild religious profanity. ("heck")

A man is seen smoking a pipe on more than one occasion.

The main character is offered a drink of whisky. He and another man partake.

The main character is shown taking Benzedrine. (another character explicitly names the drug.)

Multiple instances of cigarette smoking.

The titular "fiend" is really scary.