First published in 1989 for Advanced Dungeons & Dragons, Spelljammer is one of the most unique D&D settings of all time. It combined the traditional sword-and-sorcery fantasy trappings of the base game with the science fiction stylings of Jules Verne, the Ptolomaic model of astrophysics, and the swashbuckling of nautical fiction. It placed other existing D&D settings inside of huge crystal spheres, separated by a sea of "phlogiston." Magical ships capable of carrying people between these spheres allowed players to hop from planet to planet, having adventures in wildly different locations and even battling enemies on the seas themselves.
Spelljammer is home to dozens of unique creatures, as well as new and interesting variations of existing D&D creatures. An Unearthed Arcana article published in October 2021 titled Travelers of the Multiverse features some of the playable races from Spelljammer adapted for 5th Edition, indicating a possibility that there will be a full Spelljammer setting for the current version of the game sometime soon.
10 Autognomes Are Robotic Gnomes
These artificial creatures are built by other gnomes to serve as assistants or companions. They largely resemble gnomes, though with notably mechanical features like immovable faces, stiff gates, or distinct ticking noises. Autognomes were one of the playable races presented in the Unearthed Arcana article, with several traits that make them exciting additions to the game. They feature built-in armor, a personal bless-like effect and resistance to poison and disease.
9 Neogi Dominate Other Species
Though these creatures have been present in 5th Edition since Volo's Guide to Monsters, they actually got their start in Spelljammer. Resembling a combination of a spider and an eel, these creatures are domineering slavers capable of mind-controlling other beings. Their description in Volo's Guide hints at their extraplanetary origin, saying that they "invaded the world long ago from a remote location on the Material Plane. Neogi in Spelljammer fly between worlds in huge, spiderlike vessels called deathspiders.
8 The Giff Are Powerful Mercenaries
One of the most iconic creatures in Spelljammer are the giff, hippo-like humanoids known for their militarism and skill with firearms. They were introduced with signature black powder weaponry and dressed in naval uniforms to match.
Like the autognome, Giff are presented in the Travelers of the Multiverse article, featuring the ability to reroll 1's on damage dice and advantage on Strength checks and saving throws. The article also pokes fun at the common debate over the pronunciation of the word GIF, with different giff being split on whether their species is pronounced with a hard or soft g sound.
7 Beholder-kin Provide Some Variety To A Classic
The beholder is a classic D&D monster, and Spelljammer introduced a variety of terrifying variations on the iconic creature, collectively known as beholder-kin. The beholder hive mother is twice the size of a regular beholder, able to swallow enemies whole. Beholder directors bred specialized mounts called crawlers, centipede-like creatures with a venomous bite. Beholder mages were blind in their central eye, negating their normal anti-magic cone and allowing them to store spells in their eyestalks.
6 Xixchil Are A Variant On The Thri-Kreen
The multi-limbed insectoid people known as thri-kreen go way back in D&D's history, and they are most known for featuring prominently in the Dark Sun campaign setting. But they also received a variant form in Spelljammer, called the xixchil. They were master surgeons, known for removing limbs and replacing them with weapons and other augmentations. These creatures add a cyberpunk flair to the setting, broadening its sci-fi themes even further. Thri-kreen are present in Travelers of the Multiverse, though no reference is made to their Spelljammer counterparts.
5 Giant Space Hamsters Exemplify The Setting's Humor
Illustrating the humorous bent of much of Spelljammer's content is the giant space hamster. These creatures, which averaged nine feet in length, were bred by gnomes to power their spaceships. The hamsters would run on giant wheels, providing the necessary energy.
They came in many varieties, including the armor-plated giant space hamster, the miniature giant space hamster (about the size of a hamster), and the fire-breathing phase doppleganger giant space hamster, capable of shapechanging, shifting to the Ethereal Plane, and breathing cones of fire.
4 Murderoids Are Colossal Creatures
The fearsome murderoid really pushes the boundary between monster and force of nature. Essentially living asteroids, these creatures can grow to be up to a hundred miles long, with their own atmospheres. They lure creatures in to land on their surface, then attack them with spells like Hallucinatory Terrain, Earthquake, and Grease. The murderoid really helps capture the adventure story trope of sailors landing on an island only to discover the island itself is alive.
3 Comet Steeds Gallop Through The Stars
Though they resemble mundane horses, comet steeds are actually capable of interstellar travel on their own. They can travel freely in the phlogiston, surrounded by a silvery cloud of stardust that trails behind them like a comet's tail.
They can be tamed if found as a foal, though they are incredibly rare. The adventure Crystal Spheres, published in 1990, also featured the Ring of the Comet, a magic item capable of summoning a comet steed temporarily.
2 Radiant Dragons Can Fight Ships Alone
Any good D&D setting will have some kind of variation on the dragon, and Spelljammer is no exception. The radiant dragons, or star dragons, are truly colossal, growing to be over 1000 feet long. They are completely at home in space, and present a real threat to traveling ships if they decide to be aggressive. Their breath weapon resembles the Magic Missile spell, taking the form of bolts of energy.
1 The Arcane Are Cosmic Merchants
These creatures are essential to the Spelljammer setting. The arcane resemble blue-skinned giants with limber frames. They are consummate merchants, most famous for selling the helms that power the space-faring ships in Spelljammer. The arcane are secretive, as nobody seems to know what they do with the money they collect or where they come from. Nobody has ever seen a young arcane, leading some to believe they are immortal.