| Tri flower frond | 0.5 | Plant | Medium | 10 | 11 | | unaligned | | Adventures (Tomb of Annihilation) | | | | | | |
| Treant | 9 | Plant | Huge | 16 | 138 | | chaotic good | | Monster Manual (SRD) | 23 | 8 | 21 | 12 | 16 | 12 |
| Trapper | 3 | Monstrosity | Large | 13 | 85 | | unaligned | | Volo's Guide to Monsters | | | | | | |
| Transmuter | 5 | Humanoid (any race) | Medium | 12 | 40 | | any alignment | | Volo's Guide to Monsters | | | | | | |
| Tortle druid | 2 | Humanoid (tortle) | Medium | 17 | 33 | | lawful neutral | | Mordenkainen's Tome of Foes | | | | | | |
| Tortle | 0.25 | Humanoid (tortle) | Medium | 17 | 22 | | lawful good | | Mordenkainen's Tome of Foes | | | | | | |
| Tlincalli | 5 | Monstrosity | Large | 15 | 85 | | neutral evil | | Volo's Guide to Monsters | | | | | | |
| Titivilus | 16 | Fiend (devil) | Medium | 20 | 127 | fly | lawful evil | | Mordenkainen's Tome of Foes | | | | | | |
| Tiger | 1 | Beast | Large | 12 | 37 | | unaligned | | Monster Manual (SRD) | 17 | 15 | 14 | 3 | 12 | 8 |
| Tiamat | 30 | Fiend | Gargantuan | 25 | 615 | fly | chaotic evil | | Adventures (Tyranny of Dragons) | | | | | | |
| Thug | 0.5 | Humanoid (any race) | Medium | 11 | 32 | | any non-good alignment | | Monster Manual (SRD) | 15 | 11 | 14 | 10 | 10 | 11 |
| Thri kreen | 1 | Humanoid (thri-kreen) | Medium | 15 | 33 | | chaotic neutral | | Monster Manual | | | | | | |
| Thorny | 1 | Plant | Medium | 14 | 27 | | neutral | | Volo's Guide to Monsters | | | | | | |
| The wretched | 0.25 | Monstrosity | Small | 15 | 10 | | neutral evil | | Mordenkainen's Tome of Foes | | | | | | |
| The lost | 7 | Monstrosity | Medium | 15 | 78 | | neutral evil | | Mordenkainen's Tome of Foes | | | | | | |
| The lonely | 9 | Monstrosity | Medium | 16 | 112 | | neutral evil | | Mordenkainen's Tome of Foes | | | | | | |
| The hungry | 11 | Monstrosity | Medium | 17 | 225 | | neutral evil | | Mordenkainen's Tome of Foes | | | | | | |
| The angry | 13 | Monstrosity | Medium | 18 | 255 | | neutral evil | | Mordenkainen's Tome of Foes | | | | | | |
| Tarrasque | 30 | Monstrosity (titan) | Gargantuan | 25 | 676 | | unaligned | Legendary | Monster Manual (SRD) | 30 | 11 | 30 | 3 | 11 | 11 |
| Tanarukk | 5 | Fiend (demon, orc) | Medium | 14 | 95 | | chaotic evil | | Volo's Guide to Monsters | 18 | 13 | 20 | 9 | 9 | 9 |
| Tabaxi minstrel | 0.25 | Humanoid (tabaxi) | Medium | 12 | 22 | | chaotic good | | Adventures (Tomb of Annihilation) | | | | | | |
| Tabaxi hunter | 1 | Humanoid (tabaxi) | Medium | 14 | 40 | | chaotic good | | Adventures (Tomb of Annihilation) | | | | | | |
| Sword wraith warrior | 3 | Undead | Medium | 16 | 45 | | lawful evil | | Mordenkainen's Tome of Foes | | | | | | |
| Sword wraith commander | 8 | Undead | Medium | 18 | 127 | | lawful evil | | Mordenkainen's Tome of Foes | | | | | | |
| Swashbuckler | 3 | Humanoid (any race) | Medium | 17 | 66 | | any non-lawful alignment | | Volo's Guide to Monsters | | | | | | |