Underground Random Encounters CR 10
| d100 | Total CR | Name | Numbers | CR | Type | Size | Book |
| 1 | 10 | Aboleth | 3 | 7 | Aberration | Huge | MM1 |
| 2 | 10 | Adult Mist Dragon | 1 | 10 | Dragon | Large | Dragons of Faerûn |
| 3 | 10 | Arachnoid Mouther | 5 | 6 | Aberration | Large | Underdark |
| 4 | 10 | Avolakia | 1 | 10 | Aberration | Large | MM2 |
| 5 | 10 | Balhannoth | 1 | 10 | Aberration | Large | MM4 |
| 6 | 10 | Bane Wraith | 2 | 8 | Undead | Medium | Heroes of Horror |
| 7 | 10 | Beacon Moth | 7 | 5 | Magical Beast | Huge | Dragon #322 |
| 8 | 10 | Blood Golem of Hextor | 2 | 8 | Construct | Large | Fiend Folio |
| 9 | 10 | Bloodhulk Crusher | 2 | 8 | Undead | Huge | MM4 |
| 10 | 10 | Bloodmote Cloud | 4 | 6 | Undead | Fine | Libris Mortis |
| 11 | 10 | Bodak Five-Headed Hydra | 2 | 8 | Undead | Huge | Dragon Compendium - Volume I |
| 12 | 10 | Bonedrinker | 5 | 6 | Undead | Medium | MM3 |
| 13 | 10 | Brain Golem | 1 | 10 | Construct | Large | Fiend Folio |
| 14 | 10 | Brass Golem | 1 | 10 | Construct | Large | MM2 |
| 15 | 10 | Bronze Serpent | 1 | 10 | Construct | Huge | MM2 |
| 16 | 10 | Cadaver Golem | 2 | 8 | Construct | Large | Heroes of Horror |
| 17 | 10 | Cave Ankylosaurus | 5 | 6 | Animal | Large | Miniatures Handbook |
| 18 | 10 | Cave Troll | 2 | 8 | Giant | Large | MM3 |
| 19 | 10 | Cinderspawn | 5 | 6 | Undead | Large | Libris Mortis |
| 20 | 10 | Clay Golem | 1 | 10 | Construct | Large | MM1 |
| 21 | 10 | Cloaker | 7 | 5 | Aberration | Large | MM1 |
| 22 | 10 | Colossal Animate Object | 1 | 10 | Construct | Colossal | MM1 |
| 23 | 10 | Crypt Chanter | 3 | 7 | Undead | Medium | Libris Mortis |
| 24 | 10 | Deepspawn | 1 | 10 | Aberration | Huge | Lost Empires of Faerûn |
| 25 | 10 | Dire Lion Effigy | 5 | 6 | Construct | Large | Complete Arcane |
| 26 | 10 | Dust Wight | 3 | 7 | Undead | Medium | MM3 |
| 27 | 10 | Elder Psurlon | 2 | 8 | Aberration | Medium | Lords of Madness |
| 28 | 10 | Ethereal Ooze | 1 | 10 | Ooze | Huge | Fiend Folio |
| 29 | 10 | Evolved Wraith | 5 | 6 | Undead | Medium | Libris Mortis |
| 30 | 10 | Fire Spectre | 5 | 6 | Undead | Medium | Ghostwalk |
| 31 | 10 | Flesh Golem | 3 | 7 | Construct | Large | MM1 |
| 32 | 10 | Forsaken Shell | 4 | 6 | Undead | Medium | Libris Mortis |
| 33 | 10 | Ghost 5th-Level Human Fighter | 3 | 7 | Undead | Medium | MM1 |
| 34 | 10 | Gravetouched Ghoul 6th-Level Human Monk | 3 | 7 | Undead | Medium | Libris Mortis |
| 35 | 10 | Hook Horror | 5 | 6 | Aberration | Large | MM2 |
| 36 | 10 | Huecuva | 3 | 7 | Undead | Medium | Fiend Folio |
| 37 | 10 | Ineffable Horror | 7 | 5 | Aberration | Large | Underdark |
| 38 | 10 | Juvenile Brainstealer Dragon | 1 | 10 | Dragon | Large | Dragon #337 |
| 39 | 10 | Juvenile Deep Dragon | 1 | 10 | Dragon | Medium | Monsters of Faerûn |
| 40 | 10 | Juvenile Hex Dragon | 2 | 8 | Dragon | Large | Dragon #343 |
| 41 | 10 | Juvenile Mist Dragon | 5 | 6 | Dragon | Medium | Dragons of Faerûn |
| 42 | 10 | Juvenile Shadow Dragon | 2 | 8 | Dragon | Medium | Draconomicon |
| 43 | 10 | Kigrid | 7 | 5 | Aberration | Medium | Lords of Madness |
| 44 | 10 | Knell Beetle | 1 | 10 | Vermin | Large | MM3 |
| 45 | 10 | Krathbairn | 3 | 7 | Outsider | Medium | Dragons of Faerûn |
| 46 | 10 | Leechwalker | 1 | 10 | Vermin | Medium | MM2 |
| 47 | 10 | Legendary Ape | 3 | 7 | Animal | Medium | MM2 |
| 48 | 10 | Legendary Tiger | 1 | 10 | Animal | Large | MM2 |
| 49 | 10 | Lifeleech Otyugh | 2 | 8 | Aberration | Large | MM3 |
| 50 | 10 | Lion Topiary Guardian | 3 | 7 | Plant | Large | MM3 |
| 51 | 10 | Lolth’s Sting | 6 | 5 | Humanoid | Medium | MM4 |
| 52 | 10 | Madcrafter of Thoon | 1 | 10 | Aberration | Huge | MM5 |
| 53 | 10 | Medusa Mumia | 2 | 8 | Undead | Medium | Ghostwalk |
| 54 | 10 | Mind Flayer | 2 | 8 | Aberration | Medium | MM1 |
| 55 | 10 | Mind Flayer Thoon Disciple | 1 | 10 | Aberration | Medium | MM5 |
| 56 | 10 | Minotaur of Legend | 4 | 6 | Outsider | Large | MM2 |
| 57 | 10 | Mohrg | 2 | 8 | Undead | Medium | MM1 |
| 58 | 10 | Mummy | 7 | 5 | Undead | Medium | MM1 |
| 59 | 10 | Myconid Circle Leader | 5 | 6 | Plant | Large | MM2 |
| 60 | 10 | Nerve Swimmers | 1 | 10 | Aberration | Fine | Dragon #337 |
| 61 | 10 | Plague Spewer | 1 | 10 | Undead | Huge | MM3 |
| 62 | 10 | Quth-maren | 3 | 7 | Undead | Medium | Fiend Folio |
| 63 | 10 | Ripper | 5 | 6 | Aberration | Medium | Cityscape |
| 64 | 10 | Rot Grub Swarm | 4 | 6 | Vermin | Diminutive | Dungeonscape |
| 65 | 10 | Ruin Elemental | 1 | 10 | Elemental | Large | MM5 |
| 66 | 10 | Runic Guardian | 1 | 10 | Construct | Large | MM2 |
| 67 | 10 | Salt Mummy | 2 | 8 | Undead | Medium | MM3 |
| 68 | 10 | Scaladar | 2 | 8 | Construct | Large | Waterdeep |
| 69 | 10 | Scarab Beetle Swarm | 1 | 10 | Vermin | Fine | Fiend Folio |
| 70 | 10 | Scyther of Thoon | 5 | 6 | Construct | Medium | MM5 |
| 71 | 10 | Shaboath | 1 | 10 | Construct | Large | Lords of Madness |
| 72 | 10 | Shredstorm | 2 | 8 | Construct | Fine | MM3 |
| 73 | 10 | Slaughter Wight | 2 | 8 | Undead | Medium | Libris Mortis |
| 74 | 10 | Spectre | 3 | 7 | Undead | Medium | MM1 |
| 75 | 10 | Stonesinger | 3 | 7 | Aberration | Large | MM3 |
| 76 | 10 | Swordwraith | 3 | 7 | Undead | Medium | Fiend Folio |
| 77 | 10 | Terror Vampire, 7th Level Elf Sorcerer | 1 | 10 | Undead | Medium | Dragon #348 |
| 78 | 10 | Thayan Golem | 2 | 8 | Construct | Medium | Monsters of Faerûn |
| 79 | 10 | Thunder | 5 | 6 | Outsider | Medium | Dragon #317 |
| 80 | 10 | Uchuulon | 5 | 6 | Aberration | Large | Stormwrack |
| 81 | 10 | Umber Hulk | 3 | 7 | Aberration | Large | MM1 |
| 82 | 10 | Umber Hulk Zombie | 7 | 5 | Undead | Large | MM1 |
| 83 | 10 | Umbral Displacer Beast | 4 | 6 | Undead | Large | Libris Mortis |
| 84 | 10 | Underdark Landwyrm | 2 | 8 | Dragon | Large | Draconomicon |
| 85 | 10 | Very young Brainstealer Dragon | 5 | 6 | Dragon | Large | Dragon #337 |
| 86 | 10 | Very young Deep Dragon | 5 | 6 | Dragon | Small | Monsters of Faerûn |
| 87 | 10 | Voidwraith | 5 | 6 | Undead | Medium | Libris Mortis |
| 88 | 10 | War Bat | 7 | 5 | Animal | Huge | MM2 |
| 89 | 10 | Widowmaker | 1 | 10 | Vermin | Large | Drow of the Underdark |
| 90 | 10 | Wraith | 7 | 5 | Undead | Medium | MM1 |
| 91 | 10 | Young Adult Hex Dragon | 1 | 10 | Dragon | Large | Dragon #343 |
| 92 | 10 | Young adult Mist Dragon | 2 | 8 | Dragon | Large | Dragons of Faerûn |
| 93 | 10 | Young Amethyst Dragon | 3 | 7 | Dragon | Medium | MM2 |
| 94 | 10 | Young Chromium Dragon | 3 | 7 | Dragon | Medium | Dragon #356 |
| 95 | 10 | Young Cobalt Dragon | 3 | 7 | Dragon | Medium | Dragon #356 |
| 96 | 10 | Young Deep Dragon | 2 | 8 | Dragon | Medium | Monsters of Faerûn |
| 97 | 10 | Young Emerald Dragon | 3 | 7 | Dragon | Medium | MM2 |
| 98 | 10 | Young Hex Dragon | 5 | 6 | Dragon | Medium | Dragon #343 |
| 99 | 10 | Young Sapphire Dragon | 3 | 7 | Dragon | Medium | MM2 |
| 100 | 10 | Young Shadow Dragon | 5 | 6 | Dragon | Small | Draconomicon |
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