Snakebite: Achievement STEAM of Wolfenstein 2: The New Colossus

This can be done at the start of chapter 'A New Suit' / 'Ein Neuer Anzug', after being executed by the Nazis during an unskippable cutscenes and having your head detached from your body. Afterwards, you get a new body and can choose between 3 upgrades: Ramshackles, Constrictor Harness, Battle Walker.
For this trophy you need to choose the Constrictor Harness. While crouching, the Harness will activate automatically when you can do a stealth takedown. So sneak up to an enemy and use this upgrade to kill an enemy to earn the trophy.