Here is the full list of all 14 Worms Clan Wars achievements.
Kill a total of 300 enemy worms
Kill a total of 100 enemy worms
Complete "Meat In The Middle"
Complete a multiplayer match using your personally created landscape
Fully customise your worms
Kill a total of 10 enemy worms
Create your own clan, complete with emblem
Complete "The Mission Before Time"
Complete "Worm On Trap"
Complete "The Class Act"
Complete "Fugu Fountain"
Defeat the evil Lord Mesmer
Complete all Worm Ops missions
Win a ranked Clan Match