This is a list of achievements or medals that don’t exist for various reasons.
Saviour - Get a showstopper medal to tie or gain the lead in the final seconds of a match.
Clingy Guy - Kill an enemy with a plasma grenade you’re stuck to.
Seeing Stars - Kill an enemy using a ground pound with an air-assassination.
Sierra Tango Foxtrot Uniform - Mute everyone in a matchmade game.
You Dropped Something - Pick up an Infected’s energy sword as a survivor.
Bullfighter - Board and destroy 3 vehicles in a single game.
Helpful, but not Ideal - Get the most assists in a free-for-all match.
It’s Bacon Now - Destroy an enemy-occupied warthog with an incineration canon.
Your Upstair Neighbor - Kill 3 enemy spartans using the melee attack from a mantis in a single match.