The Leviathans Add-on for Stellaris has 12 achievements.
Hatch the egg
Destroy a wraith
Restore an ancient warship
Defeat a horrifying invader
Uncover the secrets of an ancient fortress
Birth a new universe
Support the Artisan Troupe for 10 years
Recruit a scientist from the Curators
Purchase a rare resource from the Traders
Take a trophy from a stellar being
Destroy an enclave
Lead the non-aligned powers to victory against an awakened empire