| Name | CR | Type | Environment |
| Aanung-an | 4 | undead | any |
| Acrochor | 8 | animal | warm hills or mountains (Nejeor V) |
| Aeon Guard | 3 | humanoid (human) | any (Azlanti Star Empire) |
| Aeon Guard, Aeon Guard Specialist | 7 | humanoid (human) | any (Azlanti Star Empire) |
| Aeon Stone Network | 7 | construct (magical, swarm, technological) | any |
| Aeon, Tekhoinos | 10 | outsider (aeon, extraplanar) | any (Outer Planes) |
| Aerial Devil | 2 | animal | cold and temperate forests |
| AHAV | 12 | construct (technological) | any |
| Akata | 1 | aberration | any |
| Akata, Void Zombie | 1 | undead | any |
| Anacite, Anacite Ambassador | 6 | construct (technological) | any (Aballon) |
| Anacite, Anacite Laborer | 7 | construct (technological) | any (Aballon) |
| Anacite, Anacite Predator Drone | 10 | construct (technological) | any (Aballon) |
| Anacite, Anacite Wingbot | 1/2 | construct (technological) | any (Aballon) |
| Anassanoi | 5 | humanoid (anassanoi) | any (Kahlannal) |
| Angel, Barachius | 7 | outsider (angel, extraplanar, good) | any good-aligned planes |
| Angel, Exodus | 17 | outsider (angel, good, extraplanar) | any (Heaven) |
| Animated Armor, Animated Lashunta Mind Mail III | 16 | construct (magical, technological; armor) | any |
| Animated Armor, Animated Lictor Hellknight Plate | 5 | construct (magical, technological; armor) | any |
| Apari | 7 | vermin | temperate or warm plains |
| Apari, Apari Constituent | 2 | vermin | temperate or warm plains |
| Aqlath | 16 | monstrous humanoid | any (Lathlath IV) |
| Archon, Power Archon | 5 | outsider (archon, extraplanar, good, lawful) | any (Heaven) |
| Arquand Gazelle | 4 | animal | any forests, hills, or plains (Arquand) |
| Ashypsozoan | 10 | aberration | any (Ashypso) |
| Assembly Ooze | 1 | ooze (technological) | any urban |
| Asteray | 12 | fey | any vacuum |
| Atrocite | 10 | outsider (chaotic, evil, native) | any |
| Autofly Swarm | 3 | construct (swarm, technological) | any (Aballon) |
| Azata, Avigwyr | 13 | outsider (azata, chaotic, extraplanar, good) | any (Elysium) |
| Azata, Tritidair | 8 | outsider (azata, chaotic, extraplanar, good) | any (Elysium) |
| Azer | 2 | outsider (extraplanar, fire) | any (Plane of Fire) |