 Ice Troll King (Nightmare Zone)AggressiveM | | | 0 | Trolls |
| Ice wolfAggressiveM | 70 | | 657 | Wolves |
 IcefiendM | | | 0 | Icefiends |
| Imp | | | 364 | |
 Iron dragonAggressiveM | | | 0 | Metal Dragons |
 Jaguar warrior (Deadman)AggressiveM | | 21 | 0 | |
| JogreM | | | 1,034 | |
 Jungle Demon (Nightmare Zone)AggressiveM | | | 1,125 | |
 Justiciar Zachariah (Deadman)AggressiveM | | 43 | 0 | |
| Kalphite Queen (Echo)AggressiveM | 561 | 38 | 0 | Kalphite, Bosses |
| Kalphite Queen (Realm of Memories)M | 255 | | 0 | |
 Kamil (Nightmare Zone)AggressiveM | | | 180 | Ice Warriors |
 Karamel (Nightmare Zone)AggressiveM | | | 200 | |
 Khazard warlord (Nightmare Zone)AggressiveM | | | 40 | |
 King Black Dragon (Deadman)AggressivePoisonM | | 25 | 0 | Black Dragons, Bosses |
 King black dragon (Realm of Memories)M | 240 | | 0 | |
 King Roald (Nightmare Zone)AggressiveM | | | 40 | |
 King Scorpion (Realm of Memories) | 30 | | 0 | |
 Knight of Ardougne (Song of the Elves)M | | | 0 | |
| Knight of SaradominM | | | 40 | |
| KolodionAggressivePoisonM | | 20 | 0 | |
 Koschei the deathlessAggressiveM | 30 | 3 | 0 | |
| KrakenM | 255 | 28 | 18.2K | Cave Kraken, Bosses |
 Lava beastAggressiveM | | 18 | 0 | |
| Lesser demonAggressive | | | 0 | Lesser Demons |
 Lesser demon (Realm of Memories) | 79 | | 0 | |
| Lesser demon (The Scar)M | | | 0 | |
 Lizard man (Realm of Memories) | 35 | | 0 | |
| LizardmanAggressiveM | 60 | | 0 | Lizardmen |
 Lizardman shaman (Chambers of Xeric)AggressiveM | | 65 | 242 | Lizardmen |
| Locust riderAggressiveM | 90 | | 2,624 | Scabarites |
 Lucky implingM | 10 | N/A | 0 | |
| LynxM | | 3 | 40 | |
| Mad AngelM | | 31 | 30.8K | |
 Magic MarkAggressiveM | | 18 | 0 | |
 Magpie implingM | 10 | N/A | 0 | |
 Malevolent Mage (Deadman)AggressiveM | | | 0 | |
 Me (Nightmare Zone)AggressiveM | | | 40 | |
 Medium BarrierM | 100 | N/A | 0 | |
 Minotaur | | | 47 | Minotaurs |
| Monk | | 1 | 40 | |
| Monk of Zamorak | | | 202 | |
| Monk of Zamorak (Paterdomus)M | | | 202 | |
 Monkey ZombieAggressiveM | | | 0 | Monkeys, Zombies |
| Mosquito swarmAggressiveM | | 1 | 0 | |
| Moss giantAggressive | | 6 | 0 | Moss Giants |
 Moss Guardian (Nightmare Zone)AggressiveM | | | 242 | |
| Mountain trollAggressiveM | 90 | | 420 | Trolls |
 Mounted terrorbird gnomeM | | | 40 | Birds |
| MournerM | | | 0 | |