The The Crimson Court Add-on for Darkest Dungeon has 15 achievements.
Have your entire roster affected by the crimson curse
Kill an ally while under the Curse
Lose a hero to Wasting Away from the Curse
Rescue someone
Defeat the Countess
Defeat the Viscount
Defeat the Fanatic
Defeat the Baron
Collect The Invitation
Contract the Crimson Curse via contagion
Get infected by the Crimson Curse
Collect your first Trinket Set
Build The Red Hook
Build your first district building
Recruit a flagellant