SRD & OGL creatures — full stat blocks. Each entry links its source.
| Name | Type | Size | CR | Source |
|---|---|---|---|---|
| Ice Maiden | Fey | Medium | 6 | Tome of Beasts 2023 |
| Ice Mephit | Elemental | small | 1/2 | Black Flag SRD |
| Ice Mephit | Elemental | Small | 1/2 | 5e Core Rules |
| Ice Mephit | Elemental | Small | 1/2 | Level Up Advanced 5e Monstrous Menagerie |
| Ice Urchin | Monstrosity | Large | 1 | Tome of Beasts 3 |
| Ice Willow | Plant | Large | 6 | Tome of Beasts 3 |
| Ice Worm | Monstrosity | Gargantuan | 15 | Level Up Advanced 5e Monstrous Menagerie |
| Iceworm | Monstrosity | Small | 1 | Tome of Beasts 3 |
| Ichneumon | Monstrosity | Large | 11 | Creature Codex |
| Ijiraq | Fey | Medium | 7 | Creature Codex |
| Ikuchi | Elemental | Gargantuan | 8 | Tome of Beasts 2 |
| Illhveli, Kembingur | Monstrosity | Gargantuan | 12 | Tome of Beasts 2 |
| Illhveli, Nauthveli | Monstrosity | Gargantuan | 16 | Tome of Beasts 2 |
| Imp | Fiend | Tiny | 1/2 | Level Up Advanced 5e Monstrous Menagerie |
| Imp | Fiend | Tiny | 1 | 5e Core Rules |
| Imp | Fiend | tiny | 1 | Black Flag SRD |
| Imp Familiar | Fiend | Tiny | 1/2 | Level Up Advanced 5e Monstrous Menagerie |
| Imperator | Monstrosity | Huge | 11 | Tome of Beasts 3 |
| Imperial Dragon Wyrmling | Dragon | Medium | 3 | Tome of Beasts 2 |
| Imperial Ghoul | Undead | Medium | 4 | Tome of Beasts 2023 |
| Imy-Ut Ushabti | Monstrosity | Medium | 3 | Tome of Beasts |
| Incandescent One | Celestial | Medium | 9 | Tome of Beasts 3 |
| Incarnate Gloom | Undead | Gargantuan | 13 | Tome of Beasts 2 |
| Incinis | Elemental | Large | 10 | Creature Codex |
| Infernal Centaur | Fiend | Medium | 4 | Tome of Beasts 2 |
| Infernal Knight | Fiend | Medium | 16 | Creature Codex |
| Infernal Swarm | Fiend | Huge | 12 | Tome of Beasts 2 |
| Initiate of the Elder Elementals | Humanoid | Small | 2 | Tome of Beasts 2 |
| Ink Devil | Fiend | Small | 2 | Tome of Beasts 2023 |
| Ink Devil | Fiend | Small | 2 | Tome of Beasts |
| Insatiable Brood | Swarm | medium | ||
| Insect, Swarm of Insects | Swarm | |||
| Intellect Devourer | Aberration | Tiny | 3 | Level Up Advanced 5e Monstrous Menagerie |
| Invisible Stalker | Elemental | Medium | 6 | Level Up Advanced 5e Monstrous Menagerie |
| Invisible Stalker | Elemental | medium | 6 | Black Flag SRD |
| Invisible Stalker | Elemental | Medium | 6 | 5e Core Rules |
| Ooze |
| Medium |
| 2 |
| Tome of Beasts 2 |
| Construct |
| Small |
| 8 |
| Tome of Beasts |
| Construct |
| Small |
| 8 |
| Tome of Beasts 2023 |
| Beast |
| Huge |
| 5 |
| Tome of Beasts 3 |
| Ooze |
| Large |
| 4 |
| Creature Codex |
| Construct |
| Tiny |
| 1/4 |
| Creature Codex |
| 3 |
| Black Flag SRD |
| Beast |
| small |
| 1/4 |
| Black Flag SRD |
| Beast |
| small |
| 0 |
| Black Flag SRD |
| Beast |
| large |
| 3 |
| Black Flag SRD |
| Beast |
| medium |
| 1/2 |
| Black Flag SRD |
| Beast |
| tiny |
| 0 |
| Black Flag SRD |
| medium |
| 1/2 |
| Black Flag SRD |
| Ooze |
| Small |
| 5 |
| Tome of Beasts 3 |