| Name | Attribute | Level | Type |
|---|---|---|---|
| Outer Box 2 | - | 1 | Interactive |
| Outer Box 12 | - | 1 | Interactive |
| Outer Box 11 | - | 1 | Interactive |
| Outer Box 10 | - | 1 | Interactive |
| Outer Box 1 | - | 1 | Interactive |
| Out of control mercenary | 58 | General Monster | |
| Out of control mercenary | 58 | General Monster | |
| Out of control fighter | 58 | General Monster | |
| Out of control fighter | 58 | General Monster | |
| Out of control cavalry | 58 | General Monster | |
| Out of control cavalry | 58 | General Monster | |
| Otherworldly Goblin Grandmaster | 80 | General Monster | |
| Otherworldly Goblin | - | 1 | General |
| Otherworldly Goblin | 83 | General Monster | |
| Otherworldly Eye Demon | - | 1 | General Monster |
| Otherworld Walker Punishment | 65 | World Boss | |
| Otherworld Walker Crime | 65 | World Boss | |
| Otherworld Judge Frasho | 72 | Boss Monster | |
| Ossifighter Boney Prince Charlie | 56 | Elite Monster | |
| Osprae | - | 10 | Elite Monster |
| Osprae | - | 36 | Elite Monster |
| Osprae | - | 20 | Elite Monster |
| Osprae | - | 40 | Elite Monster |
| Osprae | - | 58 | Elite Monster |
| Osprae | - | 67 | Elite Monster |
| Osprae | - | 22 | Elite Monster |
| Osprae | - | 29 | Elite Monster |
| Osprae | - | 28 | Elite Monster |
| Osprae | - | 69 | Elite Monster |
| Osprae | - | 81 | Elite Monster |
| Osprae | - | 35 | Elite Monster |
| Osprae | - | 42 | Elite Monster |
| Osprae | - | 51 | Elite Monster |
| Osprae | - | 52 | Elite Monster |
| Osprae | - | 55 | Elite Monster |
| Osprae | - | 8 | Elite Monster |
| Osprae | - | 82 | Elite Monster |
| Osprae | - | 32 | Elite Monster |
| Osprae | - | 25 | Elite Monster |
| Osprae | - | 56 | Elite Monster |
| Osprae | - | 57 | Elite Monster |
| Osprae | - | 91 | Elite Monster |
| Osprae | - | 107 | Elite Monster |
| Osprae | - | 38 | Elite Monster |
| Osprae | - | 34 | Elite Monster |
| Osprae | - | 47 | Elite Monster |
| Osprae | - | 6 | Elite Monster |
| Osprae | - | 71 | Elite Monster |
| Osprae | - | 19 | Elite Monster |
| Osprae | - | 44 | Elite Monster |