Lt. Ellen Ripley is the sole survivor of the Nostromo tragedy, in which an unidentified alien organism popped out of her buddy's chest and proceeded to kill the ever-loving hell out of every single one of her crew-mates. Though she's haunted by the experience, she demonstrates incredible resourcefulness, grace under pressure, and the strength to do whatever it takes to survive.
20th Century Fox
Or, ya know, not.
While this looks like a pretty intense match-up at first, it's actually extremely one-sided: Krueger can only attack Ripley through her dreams, and Ripley's dreams are full of murderous insectoid aliens with acid blood. You might think that Freddy can control them, but I beg to differ: In A Nightmare On Elm Street 3: Dream Warriors, we learn that dreamers can use their memories and fantasies to their advantage, and I'm pretty sure the traumatic memory of an alien attack is more powerful than Freddy's weird and poorly explained magic. So, in the mashup, titled A Nightmare On The Sulaco, we see ...
INT. HOSPITAL HALLWAY - NIGHT
A MAN in a red and green sweatshirt and fedora slowly makes his way down the hallway, backlit by fluorescent lights in a really scary way. Fans of the horror know him as FREDDY KRUEGER, the DREAM DEMON who BLENDED JOHNNY DEPP IN A BED. People who aren't fans of horror think he's a MEN'S RIGHTS ACTIVIST who shops at GOODWILL.