Prior to the implementation of content into the Calamity Mod, it may be illustrated as concept art in order to give direction as to how the content should appear when created. Concept art can have varying degrees of influence on the final product, ranging from general inspiration to a guide on direct implementation, and may include labels to describe certain aspects of the content in question.
The Calamity Mod has received concept art for bosses, enemies, biomes, weapons, armor sets, lore characters, and other things.
A drawing of Crabulon's current design - by Poly
A drawing used as a basis for The Hive Mind's current design - by IbanPlay
A drawing used as a basis for The Slime God's current design - by Xelo
A drawing of Cryogen's current design with all of its phases - by Nitro
A drawing of Anahita's second design, named "The Siren" at the time - by Ziggums
A drawing of Anahita's current design - by Nitro
A drawing of Anahita's current design - by Inanis
An early concept for The Leviathan's current design - by Ziggums
An early concept for The Leviathan's current design - by Ziggums
An early concept for The Leviathan's current design - by Ziggums
A higher quality iteration of the previous concept sketch - by Ziggums
A drawing used as a basis for The Leviathan's current design - by Nitro
An Astrageldon Slime rework concept showcasing early versions of Aureus Spawns - by Nitro
A drawing used as a basis for Astrum Aureus' sprites - by Nitro
A sketched concept for The Plaguebringer Goliath's current design - by Ziggums
A sketched concept for Ravager's original design - by Ziggums
A drawing used as a basis for Ravager's second design - by Ziggums
Scrapped concepts for Profaned Guardian redesigns to make them resemble Providence more - by Nitro
Scrapped concepts for Profaned Guardian redesigns to make them resemble Providence more - by Nitro
An early drawn concept of Dragonfolly - by Inanis
A drawn concept used as a basis for Dragonfolly's current sprite - by Inanis
A drawing used as a basis for Providence's current design - by Nitro
A concept for Providence's cocoon form for her current design - by Nitro
A drawing used as a basis for The Old Duke's sprite - by Nitro
A drawn concept of XM-05 Thanatos - by Nitro
A drawn concept of XM-05 Thanatos with its vents open - by Nitro
The original concepts for the Exo Twins, with there being three eyes instead of two - by Nitro
The final concepts for the Exo Twins - by Nitro
An earlier design for XF-09 Ares - by Vaikyia
Several earlier designs for XF-09 Ares - by Vaikyia
An earlier design for XF-09 Ares - by Nitro
The initial concept for Draedon - by Puff
A drawn concept for Draedon - by Nitro
A reference drawing for Draedon - by Nitro
A drawn concept of Draedon's recon body - by Inanis
Colored concept for Supreme Calamitas' human form - by Nitro
Sketched concepts for Supreme Calamitas' human form - by Nitro
Earlier concepts for Supreme Calamitas' brothers' current designs - by IbanPlay
Drawings of Supreme Calamitas' brothers' current designs - by IbanPlay
A drawn concept for the Primordial Wyrm's current design - by Nitro
A drawn concept for the Primordial Wyrm's current design - by Nitro
A drawing of the current Sulphurous Sea - by Popo
A concept for the Sulphurous Sea's generation - by IbanPlay
Drawn concepts for the Abyss's gameplay and mechanics - by Fabsol
A concept of the Astral Infection before it was rethemed - by Poly
A concept of the Astral Infection surface - by Nitro
A sketch of the Astral Infection's generation - by Nitro
A sketch of how the Astral Infection would be layered - by Nitro
A drawn concept for the Astral Underground's background texture - by Nitro
A concept of the Astral Underground - by Nitro
A concept of the Astral Desert - by Nitro
Early Astral tree concepts - by Nitro
Astral Tree concepts - by Puff
Astral Tree concepts - by Nitro
Astral Tree concepts - by Nitro
A drawn concept for an Astral Monolith - by Nitro
Several concepts for the 1.4.5.001 Wulfrum rework - by Popo
Drawings of several pieces of Sunken Sea content including Clams, a Sea Serpent, Mollusk armor, and a handful of items - by Popo
A drawing of several Sunken Sea enemies including a Prism-Back, Ghost Bell, Baby Ghost Bell, and an early Sea Minnow - by Aleksh
A drawing of a player in the Sunken Sea surrounded by several enemies - by Popo
A demonstration for how the Ghost Bell would be animated - by Altalyra
An earlier design for the Giant Clam - by Popo
A drawing of an earlier Nuclear Toad - by Popo
A drawing of an earlier Flak Crab and a Trilobite - by Popo
Sketches of a Flak Crab and how it attacks - by IbanPlay
A drawing of several proposed Acid Rain enemies including a Skyfin (named Flyfin here) - by Popo
Drawn concepts for the Sulphurous Skater - by Kerubii
Drawn concepts for the Cragmaw Mire (named Azufre Piercer here) - by Ox
A drawing of the Cragmaw Mire - by IbanPlay
A drawing of a Nuclear Terror - by Runefield
Several enemy concepts for the Astral Infection before its retheming - by Poly
Several earlier concepts for the Astral Infection, including an Atlas, Astral Slime, Astral Head, Astralachnea, and a Stellar Culex - by Nitro
Several drawings of Astral Infection enemies, including an Atlas, Stellar Culex, and a Sightseer Collider - by Nitro
Several drawings of Astral Infection enemies, including an Aries, Hive, and Mantis - by Aleksh
Concepts for how an Atlas would attack - by Nitro
A drawn concept for an Astral Head redesign which would later become the Nova - by Nitro
A drawing of an Astralachnea - by Nitro
A drawing of a Fusion Feeder and Hadarian - by Nitro
Several enemy concepts for the Brimstone Crag including a Despair Stone - by Purple Necromancer
A sketch of a Baby Flak Crab - by IbanPlay
Several enemy concepts for the Abyss including a Chaotic Puffer, Devil Fish, and Mirage Jelly - by Purple Necromancer
A sketch of the Scorn Eater's current design - by Nitro
A sketch of a Draconic Swarmer - by IbanPlay
Sketched concepts for some items sold by the Bandit and their upgrades - by Purple Necromancer
Sketched concepts for the Igneous Exaltation, Slime Puppet Staff, and a scrapped Golem-themed summoner weapon. - by Purple Necromancer
Sketched concepts for the Black Anurian - by Purple Necromancer
Some concepts for the Daedalus Golem Staff and its Daedalus Golem - by Nincity
A variety of concepts for the Archmage's wares - by Popo
Several more weapon concepts for the Archmage including the Arctic Bear Paw, Frostbite Blaster, and Permafrost's Concoction - by Purple Necromancer
An earlier concept for the SHPC's current design - by IbanPlay
A sketched concept for the SHPC's current design - by IbanPlay
A drawn concept for the Viral Sprout - by Nincity
A sketch of Apoctolith - by Purple Necromancer
Weapon concepts for the Ravager including the Cranium Smasher, Spikecrag Staff, Realm Ravager, and Ultimus Cleaver - by Purple Necromancer
Weapon concepts for Astrum Deus including the Star Sputter, Regulus Riot, and Starspawn Helix Staff, whose design got reworked into the Borealis Bomber - by Purple Necromancer
Sketches for how Clockwork Bow's rework would work - by IbanPlay
Some concepts for the Tactical Plague Engine - by Nincity
Sketched concepts for the Void Concentration Staff - by Purple Necromancer
A sketch for The Reaper's second sprite - by Vaikyia
A finalized sketch for The Reaper's second sprite - by Vaikyia
Some sketches showcasing multiple perspectives of the Eidolic Wail - by Popo
A Celestus redesign concept - by Nitro
A drawing of Celestus' earlier design - by Nitro
A drawing of Exo Gladius - by Nitro
Sketches for how Cinders of Lament would work - by IbanPlay
Sketches for how Gruesome Eminence would work - by IbanPlay
Sketches for how Metastasis would work - by IbanPlay
A sketch of the Voidragon - by Inanis
A drawing of a person wearing Victide armor with the Victide Hermit Helmet, while holding an Urchin Spear - by Inanis
A drawing of a person wearing Hydrothermic armor - by Inanis
A sketch of Omega Blue armor's original design - by Purple Necromancer
Another sketch of Omega Blue armor's original design, along with a second scrapped armor set - by Purple Necromancer
A drawing of the Profaned Soul Crystal and its associated player transformation - by Nincity
Sketched concepts for Luxor's Gift - by Purple Necromancer
Concepts for Luxor's Gift's projectiles - by Purple Necromancer
A sketch of the Tundra Leash and its Rimehound mount - by Purple Necromancer
Sketched concepts for the Onyx Excavator Key - by Purple Necromancer
Sketched concepts for the Onyx Excavator Key - by Purple Necromancer
Drawn concepts for the Power Cell Factory, Draedon Power Cell, and Security Chest - by Nincity
Drawn concepts for The Codebreaker and an Exo Prism - by Nincity
A drawn concept of Life Alloy - by Inanis
Drawn concepts for The Community and the Shattered Community - by Inanis
A drawing of The Sponge - by IbanPlay
A drawing of the Brimstone Locus - by IbanPlay
A drawing of Terminus, as well as Xeroc's eye which appears in the Boss Rush - by Inanis
A drawing of the mod icon - by IbanPlay
A rough concept for the Rusty Beacon Prototype's minion - by IbanPlay
A drawn concept for the Astral Crystal projectile used by Astrum Aureus and several Astral weapons - by Nitro
A drawing of the Strange Orb's Ocean Spirit - by Nitro
A drawing of the Strange Orb's Ocean Spirit out of Water - by Nitro
A sketch for how the Tainted enchantment would work - by IbanPlay
A drawing of the Flamsteed Ring's Andromeda mech - by IbanPlay