Full list of all 52 Peglin achievements.
The base game contains 32 achievements, and there are 3 DLC packs containing 20 achievements.
Complete Cruciball Level 20
Win a run after accepting the vampire's deal but skipping the infernal ingot.
Die while defeating the Mines' boss
Bring an Egg to the peglin chef
Defeat a Rainbow Slime
Win a run with only your class relic
Win a run with only level 1 orbs
Completely fill one entry in the Encirclepedia's Bestiary
Collect your first monster trading card
Throw a Rigged Bomb after being eaten by the Slime Boss
Defeat the Pigment of Imagination without destroying any paintings
Convert or Destroy 3 dull pegs while fighting the Demon Wall
Defeat all 4 Qaballistic Ruins in the same turn
Deal 1000 damage to the Super Sapper in one battle by detonating adjacent Sappers
Defeat Thesaurosus with no coins remaining in the pegboard
Send a summoned demon squirrel into a black hole
Defeat the Painbow (slime)
Defeat the Orbserver of Radia
End the first phase of the Orbserver battle early by destroying all of its protective crystal pegs
Apply Yolk to the Observer