This page contains a detailed walkthrough for Mimic Massacre, one of the achievements found in Prey. The trophy is a reward for killing 5 Mimes in less than 5 seconds. As one of the tougher achievements, Mimic Massacre requires a brief build-up and a little luck.
The reason for this is that encountering 5 Mimes in the same location is a very rare occurrence, and happens only in a few locations around the base. We recommend visiting level three of Psychotronics, the area beyond the Aritium, in which you've received a mandatory tutorial for your Scope.
The attempt requires some preparation. You'll need to find Typhoon Lure and a Recycling Charge - both these items can be found nearby (e.g. lab B - the location of Typhoon Lure is shown on the screenshot above)
Make your way to the Annalise Gallegos office that is located in Lab B. You'll encounter a large window sealed by a GLOO cannon. Save your progress, as the chance of you getting the achievement during your first try is slim.
Remove the glue by firing at it with the shotgun and use the Typhoon Lure. The office is inhabited by 5 Mimes, and you should be able to attract all of them.
Storm the room and use the opportunity to throw a Recycling Charge at the attracted opponents. If everything went smoothly, the blast should suck all five creatures in, completing the requirement and unlocking the trophy in question. However, in case a single enemy managed to avoid the blast (e.g. one of the monsters has escaped through the window), use a firearm to eliminate it, or... try again - you may be able to catch the whole group with a single, well-performed action.