| Kal'gerion demon (The Shadow Reef) (Normal mode) [] | 45–55 | 1/153,600 |
| Kalphite Guardian [] | 1 | 1/2,912.71, 2 rolls |
| Kalphite Guardian [] | 45–55 | 1/3,355,443.2, 2 rolls |
| Kalphite Guardian [] | 1 | 1/2,000 |
| Kalphite Guardian [] | 45–55 | 1/256,000 |
| Kalphite King [] | 1 | 1/400, 3 rolls |
| Kalphite King [] | 45–55 | 1/51,200, 3 rolls |
| Kalphite Queen [] | 1 | 1/1,323.96, 4 rolls |
| Kalphite Queen [] | 45–55 | 1/1,525,201.45, 4 rolls |
| Kalphite Soldier [] | 1 | 1/3,640.89 |
| Kalphite Soldier [] | 45–55 | 1/4,194,304 |
| Kalphite Worker [] | 1 | 1/7,281.78 |
| Kalphite Worker [] | 45–55 | 1/8,388,608 |
| Kerapac, the bound (Hard mode) [] | 30–52 | 10/100, 3 rolls |
| Kerapac, the bound (Normal mode) [] | 17–25 | 10/100, 3 rolls |
| Kezalam, the Wanderer (Hard mode) [] | 18–22 | 65/1,000, 4 rolls |
| Kezalam, the Wanderer (Normal mode) [] | 18–22 | 65/1,000, 2 rolls |
| Killerwatt [] | 1 | 1/7,281.78 |
| Killerwatt [] | 45–55 | 1/8,388,608 |
| King Black Dragon (Members) [] | 1 | 1/831.17 |
| King Black Dragon (Members) [] | 45–55 | 1/221,405.41 |
 Kingly impling[] | 5 | 1/28 |
| Kingly impling jar [] | 5 | 1/28 |
| Knight of Ardougne [] | 1 | 1/2,912.71 |
| Knight of Ardougne [] | 45–55 | 1/3,355,443.2 |
| Kraka [] | 1 | 1/2,912.71 |
| Kraka [] | 45–55 | 1/3,355,443.2 |
| Kree'arra (Hard mode) [] | 1 | 1/800 |
| Kree'arra (Hard mode) [] | 45–55 | 1/102,400 |
| Kree'arra (Normal) [] | 1 | 1/720.81 |
| Kree'arra (Normal) [] | 45–55 | 1/101,165.07 |
| Ksenia [] | 1 | 1/58,254.22 |
| Ksenia [] | 45–55 | 1/67,108,864 |
| Laboratory slime (Big (Normal mode)) [] | 1 | 1/1,200 |
| Laboratory slime (Big (Normal mode)) [] | 45–55 | 1/153,600 |
| Lady Himiko (Normal mode) [] | 1 | 1/1,200 |
| Lady Himiko (Normal mode) [] | 45–55 | 1/153,600 |
| Lampenflora [] | 1 | 1/800 |
| Lampenflora [] | 45–55 | 1/102,400 |
| Lanzig [] | 1 | 1/58,254.22 |
| Lanzig [] | 45–55 | 1/67,108,864 |
| Lava spider (Normal mode) [] | 1 | 1/1,200 |
| Lava spider (Normal mode) [] | 45–55 | 1/153,600 |
| Lava strykewyrm [] | 1 | 7/128 |
| Lava strykewyrm [] | 1 | 1/800 |
| Lava strykewyrm [] | 45–55 | 1/102,400 |
| Lava strykewyrm (Dragonkin Laboratory) (Normal mode) [] | 1 | 1/1,200 |
| Lava strykewyrm (Dragonkin Laboratory) (Normal mode) [] | 45–55 | 1/153,600 |