aerodragon83

Been doing a multiplayer world with 2 friends. 1 plays on the XBOX One S, the other plays on PC and the XBOX Series X, and I play on PC. Whoever logs in first, hosts. I have had no issue unlocking achievements as we go, except for 1. Killing the MANT (Tighty Whities). I have the mutation for killing the MANT, but not the achievement. Do I need to start a whole new world, just for this one achievement?