 Berserk barbarian spirit | 1 | 1/256 |
| Black demon (Regular) | 1 | 1/99.3 |
| Black demon (Wilderness Slayer Cave) | 1 | 1/57.41 |
| Black dragon (Regular) | 1 | 1/154.57 |
| Black dragon (Wilderness Slayer Cave) | 1 | 1/154.57 |
 Black Guard Berserker (Red) | 1 | 1/512 |
| Black Guard (Level 25) | 1 | 1/512 |
| Black Guard (Level 48) | 1 | 1/512 |
 Black Heather | 1 | 1/256 |
| Black Knight | 1 | 1/170.67 |
 Black Knight Titan | 1 | 1/170.67 |
 Blood Reaver (Ancient Prison) | 1 | 1/512 |
 Blood-starved venator | 1 | 1/524, 3 rolls |
 Bloodthirsty Hydra | 1 | 1/512, 9 rolls |
 Bloodveld (Normal) | 1 | 1/128 |
| Blue dragon | 1 | 1/102.4 |
| Blurite rocks | 1 | 32/32,768 |
 Body Golem (Golem) | 1 | 4/52 |
 Boris | 1 | 1/2,048 |
 Borrokar | 1 | 1/2,048 |
 Brambickle | 7–10 | 10/128 |
 Brassican Mage | 1 | 1/50 |
 Bronze dragon (Standard) | 1 | 1/123.19 |
 Brutal black dragon | 1 | 1/154.57 |
 Brutal blue dragon (Catacombs of Kourend) | 1 | 1/120.92 |
 Brutal green dragon | 1 | 1/207.39 |
 Brutal red dragon | 1 | 1/154.57 |
| Bryophyta (Free-to-play) | 1 | 1/128 |
| Bryophyta (Members) | 1 | 1/128 |
 Bull shark | 1 | 1/400 |
| Calcified rocks | 1 | 32/32,768 |
 Captain Bleemadge | 6–16 | 10/128 |
 Captain Daerkin | 7–10 | 10/128 |
| Captain Dalbur | 6–16 | 10/128 |
| Captain Klemfoodle | 6–16 | 10/128 |
 Captain Ninto | 7–10 | 10/128 |
| Casket | 1 | 32/128 |
| Casket (Reward pool) | 20–30 | 1/230 |
 Catablepon (Level 49) | 1 | 1/202 |
 Cave abomination | 1 | 1/102.4, 3 rolls |
 Cave bug (Level 6) | 1 | 1/102.4 |
| Cave crawler | 1 | 1/512 |
 Cave horror (Worker) | 1 | 1/102.4 |
 Cave kraken (Cave kraken) | 1 | 1/133.33 |
 Cave slime | 1 | 1/128 |
 Cerberus | 1 | 1/1,109.33 |
| Certer | 1 | 32/150 |
 Chaos druid | 1 | 1/512 |