Here is the full list of all 13 SCP: Nine-Tailed Fox achievements.
In Singleplayer, successfully contain SCP-173.
In Singleplayer, successfully contain SCP-106.
In Waves, place 100 fuses in the fuseboxes.
In Waves, place 1000 fuses in the fuseboxes.
In Waves, kill 100 ear-bears while being in the range of their scream.
In Waves, run from SCP-939 for 5 minutes total in one game.
In Waves, kill 25 instances of SCP-939 using melee weapons.
In Team Deathmatch, win a round with less than 5 HP left.
In Waves, kill 9178 zombies.
In Waves, survive through all 12 waves in the Offices map on Keter difficulty.
In Waves, survive through all 12 waves in the Old Sewers map on Keter difficulty.
In Waves, kill 2 or more enemies with one shotgun shot, 50 times.
In Team Deathmatch, kill 50 enemies with a headshot.