| Bugbear chief | 3 | Humanoid (goblinoid) | Medium | 17 | 65 | | chaotic evil | | Monster Manual | | | | | | |
| Bugbear | 1 | Humanoid (goblinoid) | Medium | 16 | 27 | | chaotic evil | | Monster Manual (SRD) | 15 | 14 | 13 | 8 | 11 | 9 |
| Brown bear | 1 | Beast | Large | 11 | 34 | | unaligned | | Monster Manual (SRD) | 19 | 10 | 16 | 2 | 13 | 7 |
| Bronze dragon wyrmling | 2 | Dragon | Medium | 17 | 32 | fly, swim | lawful good | | Monster Manual (SRD) | 17 | 10 | 15 | 12 | 11 | 15 |
| Brontosaurus | 5 | Beast | Gargantuan | 15 | 121 | | unaligned | | Adventures (Tomb of Annihilation) | | | | | | |
| Brass dragon wyrmling | 1 | Dragon | Medium | 16 | 16 | fly | chaotic good | | Monster Manual (SRD) | 15 | 10 | 13 | 10 | 11 | 13 |
| Boneclaw | 12 | Undead | Large | 16 | 127 | | chaotic evil | | Mordenkainen's Tome of Foes | | | | | | |
| Bone naga | 4 | Undead | Large | 15 | 58 | | lawful evil | | Monster Manual | | | | | | |
| Bone devil | 9 | Fiend (devil) | Large | 19 | 142 | fly | lawful evil | | Monster Manual (SRD) | 18 | 16 | 18 | 13 | 14 | 16 |
| Boggle | 0.12 | Fey | Small | 14 | 18 | | chaotic neutral | | Volo's Guide to Monsters | | | | | | |
| Bodak | 6 | Undead | Medium | 15 | 58 | | chaotic evil | | Volo's Guide to Monsters | | | | | | |
| Boar | 0.25 | Beast | Medium | 11 | 11 | | unaligned | | Monster Manual (SRD) | 13 | 11 | 12 | 2 | 9 | 5 |
| Blue slaad | 7 | Aberration | Large | 15 | 123 | | chaotic neutral | | Monster Manual | | | | | | |
| Blue dragon wyrmling | 3 | Dragon | Medium | 17 | 52 | fly | lawful evil | | Monster Manual (SRD) | 17 | 10 | 15 | 12 | 11 | 15 |
| Blue abishai | 17 | Fiend (devil) | Medium | 19 | 195 | fly | lawful evil | | Mordenkainen's Tome of Foes | | | | | | |
| Blood hawk | 0.12 | Beast | Small | 12 | 7 | fly | unaligned | | Monster Manual (SRD) | 6 | 14 | 10 | 3 | 14 | 5 |
| Blink dog | 0.25 | Fey | Medium | 13 | 22 | | lawful good | | Monster Manual (SRD) | 12 | 17 | 12 | 10 | 13 | 11 |
| Blackguard | 8 | Humanoid (any race) | Medium | 18 | 153 | | any non-good alignment | | Volo's Guide to Monsters | | | | | | |
| Black pudding | 4 | Ooze | Large | 7 | 85 | | unaligned | | Monster Manual (SRD) | 16 | 5 | 16 | 1 | 6 | 1 |
| Black gauntlet of bane | 6 | Humanoid (human) | Medium | 16 | 51 | | lawful evil | | Adventures (Descent into Avernus) | | | | | | |
| Black dragon wyrmling | 2 | Dragon | Medium | 17 | 33 | fly, swim | chaotic evil | | Monster Manual (SRD) | 15 | 14 | 13 | 10 | 11 | 13 |
| Black bear | 0.5 | Beast | Medium | 11 | 19 | | unaligned | | Monster Manual (SRD) | 15 | 10 | 14 | 2 | 12 | 7 |
| Black abishai | 7 | Fiend (devil) | Medium | 15 | 58 | fly | lawful evil | | Mordenkainen's Tome of Foes | | | | | | |
| Bheur hag | 7 | Fey | Medium | 17 | 91 | | chaotic evil | | Volo's Guide to Monsters | | | | | | |
| Berserker | 2 | Humanoid (any race) | Medium | 13 | 67 | | any chaotic alignment | | Monster Manual (SRD) | 16 | 12 | 17 | 9 | 11 | 9 |