Here is the full list of all 61 Knight Crawlers achievements.
Create a new crawler
Spawn a group of enemies
Reach an Ancient Realm depth of 10
Reach an Ancient Realm depth of 25
Reach an Ancient Realm depth of 50
Reach an Ancient Realm depth of 100
Loot the First Terror's Artifact
Loot a unique item
Equip an offhand shield or weapon
Loot a cosmetic item
Spawn 100 enemies
Spawn 1,000 enemies
Spawn 10,000 enemies
Spawn 100,000 enemies
Defeat the Ancient Terror
Equip a crawler companion
Equip a crawler outfit
Defeat Khargos, the Dread Knight
Change your sanctuary
Allocate an Eldrasil Passive
Max out an Eldrasil Passive
Allocate a Dominion
Max out a Dominion Class
Loot a Domination Rune
Enchant an item
Loot a hidden chest
Loot a rare chest
Fight in the Crimson Arena
Create a hardcore crawler
Perish at the hands of an enemy
Perish in lava
Lose a hardcore crawler
Lose a hardcore crawler to lava
Reach a hardcore Ancient Realm depth of 10
Reach a hardcore Ancient Realm depth of 25
Reach a hardcore Ancient Realm depth of 50
Reach a hardcore Ancient Realm depth of 100
Defeat Khargos, the Dread Knight, in hardcore
Defeat the Ancient Terror in hardcore
Spawn 100 enemies in hardcore
Spawn 1,000 enemies in hardcore
Spawn 10,000 enemies in hardcore
Spawn 100,000 enemies in hardcore
Fight 100 enemies all at once
Receive essence from an Arcane Shrine
Receive a glyph from an Arcane Shrine
Receive a cosmetic item from an Arcane Shrine
Receive health from an Arcane Shrine
Wager essence at an Arcane Shrine
Gain the Undying Passive from an Arcane Shrine
Gain the Devastation Passive from an Arcane Shrine
Gain the Alacritous Passive from an Arcane Shrine
Activate a Dark Shrine
Activate an Arcane Shrine
Unlock all Cosmetic Outfits
Unlock all Cosmetic Wings
Unlock all Cosmetic Attachments
Unlock all Companions
Unlock all Sanctuaries
Unlock all Cosmetics
Get unlucky at a Wagering Shrine