| Name | Family | Level | Alignment | Creature Type | Size |
| Cavern Troll | Troll | 6 | Chaotic Evil | Giant | Large |
| Elysian Titan | Titan | 21 | Chaotic Good | Humanoid | Gargantuan |
| Frost Troll | Troll | 4 | Chaotic Evil | Giant | Large |
| Giant Snapping Turtle | Turtle | 9 | Neutral | Animal | Gargantuan |
| Giant Tick | Tick | 1 | Neutral | Animal | Small |
| Giant Toad | Toad | 2 | Neutral | Animal | Large |
| Jotund Troll | Troll | 15 | Chaotic Evil | Giant | Huge |
| Slug | Tick | 8 | Neutral | Animal | Huge |
| Snapping Turtle | Turtle | -1 | Neutral | Animal | Tiny |
| Taiga Giant | Giant | 12 | Chaotic Neutral | Giant, Humanoid | Huge |
| Taiga Linnorm | Linnorm | 19 | Chaotic Evil | Dragon | Gargantuan |
| Tallow Ooze | Ooze | 11 | Neutral | Ooze | Medium |
| Tarn Linnorm | Linnorm | 20 | Chaotic Evil | Dragon | Gargantuan |
| Tarrasque, The Armageddon Engine | Spawn of Rovagug | 25 | Chaotic Evil | Beast | Gargantuan |
| Tatzlwyrm | — | 2 | Neutral | Dragon | Medium |
| Tendriculos | — | 7 | Neutral | Fungus, Plant | Huge |
| Tengu | — | 2 | Chaotic Neutral | Humanoid | Medium |
| Terotricus | — | 19 | Chaotic Evil | Fungus | Gargantuan |
| Thanadaemon (Death Daemon) | Daemon | 13 | Neutral Evil | Fiend | Medium |
| Thanatotic Titan | Titan | 22 | Chaotic Evil | Humanoid | Gargantuan |
| Theletos | Aeon | 7 | Lawful Neutral | Monitor | Medium |
| Thrasfyr | — | 17 | Chaotic Evil | Beast | Huge |
| Thulgant | Qlippoth | 18 | Chaotic Evil | Fiend | Large |
| Thunderbird | — | 11 | Neutral | Beast | Gargantuan |
| Tick Swarm | Tick | 9 | Neutral | Animal | Large |
| Tidal Master | Elemental, Water | 9 | Neutral | Elemental | Large |
| Tiefling | Planar Scion | 3 | Chaotic Evil | Humanoid | Medium |
| Tiger | Cat | 4 | Neutral | Animal | Large |
| Titan Centipede | Centipede | 9 | Neutral | Animal | Gargantuan |
| Tixitog | — | 3 | Neutral Evil | Aberration | Medium |
| Tor Linnorm | Linnorm | 21 | Chaotic Evil | Dragon | Gargantuan |
| Totenmaske | — | 7 | Neutral Evil | Undead | Medium |
| Treerazer | — | 25 | Chaotic Evil | Fiend | Huge |
| Triceratops | Dinosaur | 8 | Neutral | Animal | Huge |
| Triton | — | 2 | Neutral Good | Humanoid | Medium |
| Troll King | Troll | 10 | Chaotic Evil | Giant | Large |
| Trollhound | — | 3 | Neutral | Beast | Medium |
| Troll | Troll | 5 | Chaotic Evil | Giant | Large |
| Trumpet Archon | Archon | 14 | Lawful Good | Celestial | Medium |
| Twigjack | — | 3 | Chaotic Evil | Fey, Plant | Tiny |
| Two-Headed Troll | Troll | 8 | Chaotic Evil | Giant | Large |
| Tyrannosaurus | Dinosaur | 10 | Neutral | Animal | Gargantuan |
| Tzitzimitl | — | 19 | Neutral Evil | Undead | Gargantuan |