| Name | CR | Type | Environment |
| Balrodd | 9 | construct (magical, technological) | any (Shadari Confederacy) |
| Barathu | 5 | aberration | any sky (Bretheda) |
| Barathu, Barathu (Early Stage) | 2 | aberration | any sky (Bretheda) |
| Barghest | 4 | outsider (evil, extraplanar, lawful, shapechanger) | any |
| Barro | | vermin Init +1; Senses blindsense (vibration) 30 ft., darkvision | any (urban) |
| Baykok | 9 | undead | any |
| Bear (Uplifted), Uplifted Bear Avenger | 4 | magical beast | any |
| Bear (Uplifted), Uplifted Bear Constellate | 7 | magical beast | any |
| Bloodbrother | 7 | magical beast (cold) | any cold (Verces) |
| Bodysnatcher Slime, Bodysnatcher Autocrat | 10 | ooze | any land |
| Bodysnatcher Slime | 3 | ooze | any land |
| Bolida, Bolida Miner | 2 | vermin | any underground |
| Bolida, Bolida Overseer | 8 | vermin | any underground |
| Bone Trooper | 3 | undead | any (Eox) |
| Bone Trooper, Bone Trooper Captain | 8 | undead | any |
| Bone Trooper, Bone Trooper Technomancer | 3 | undead | any |
| Bounty Hunters, Bounty Hunter | 10 | humanoid (pahtra) | — |
| Bounty Hunters, Notorious Bounty Hunter | 14 | monstrous humanoid | — |
| Bounty Hunters, Recovery Agent | 6 | humanoid (maraquoi) | — |
| Bounty Hunters, Skip Tracer | 1 | humanoid (kobold) | — |
| Brain Collector | 8 | aberration | any |
| Brenneri, Brenneri Ambassador | 6 | humanoid (brenneri) | any (Varturan) |
| Brenneri, Brenneri Sage | 3 | humanoid (brenneri) | any (Varturan) |
| Brood Sovereign | 20 | magical beast (aquatic, cold) | any cold aquatic (Nisis) |
| Bryrvath | 15 | aberration (chaotic, evil) | any (Aucturn) |