I have long held that "The Doomsday Machine" is incredibly, well, what back in the sixties we called "dirty".

Consider the machine: From in front, its maw is a classic vagina dentata, while from the side it's, well, very phallic (though I've also heard it compared to horn-o-plenty).

Consider the action:

Decker, armed with a full starship, attempts to slay the thing and perishes.

Kirk, the Hero, armed only with a shuttle, rams it into the thing's, uh, opening.

On the Enterprise, they desparately try to beam him home.

The shuttle goes in. From a side view, the thing ... ejaculates.

And only then does Kirk appear on the transporter pad. Sweaty, breathing hard... from piloting a shuttle?

I swear, if he turned around, you'd see fingernail marks down his back.

Spinrad, of course, denies any such intentions.