The The Reaper's Due Add-on for Crusader Kings II has 12 achievements.
Kill a character with the Immortal trait.
Become immortal.
Survive the End Times.
Recover from the Black Death.
Die from the Black Death.
From Seclusion, kick someone out who had the plague.
From Seclusion, kick someone out who did not have the plague.
Contract three symptoms.
Build a Hospital.
Go into Seclusion.
Have elephants trample the Pope/Caliph.
Become One-Eyed, One-Legged and One-Handed.