The Children of the Worm Add-on for Back 4 Blood has 13 achievements worth 130 gamerscore.
Complete all Act 5 maps on No Hope difficulty.
Complete all Act 5 maps on Nightmare difficulty or higher.
Complete all Act 5 maps on Veteran difficulty or higher.
Complete all Act 5 maps on Recruit difficulty or higher.
Bring 11 Duffel Bags to Saferooms.
Find the Secret in Act 5.
Kill a Crone with the Bow.
Kill a Slasher with Iron Claws.
Hit a Pusflinger with a Bait Jar.
Jump over a Cultist Bear Trap without triggering it.
Have at least five different Food Buffs active at one time.
Use a Smoke Grenade to become hidden while at Critical Health.
Kill a Sniper with a Sniper Rifle.