Help me out, guys!!

I saw this a looong time ago, I was a kid then and from what I can remember it was like a Thing rip-off with a group of characters in a militar base or something like that.

This creature took the form of your worst fear and transform in it to kill you (yep, just like in Stephen King´s “IT”) like an old scientist with the fear of an old creepy circus freak-like woman and other character who was looking up for a test monkey or something and then she´s killed bye the creature trasnformed into a mutan monkey….WTF

The most prominent part that I remember is the ending with a lady scientist opening some kind of multi-dimensional portal to the creature´s world and looking through it saying “There are millions of them” and getting killled.

There´s also a part with two test subjects (male and female) totally naked in some crionic tubes…..just for fan-service.

Well, that´s it….the only other part that I remember mostly is when the black comic relief guy dies off-screen, like in a “woosh” from the MC perpective at the other side of an elevator.

I hope you can help me!! 😀