| “ | Unlike humans, the Strogg aren’t just one race. They represent a combination of captured and processed races; a bloody marriage between bone and metal, flesh and machine. | ” |
—Quake II manual | ||
The enemies in Quake II are the Strogg - a vicious cybernetic race with mysterious origins. They are composed of various assimilated races merged with advanced machinery. A few specimens from the planet's heavily mutated (and carnivorous) fauna are also among the monsters.
| Attack : Damage |
| Monster | Health | 1 | 2 | 3 |
| Light Guard | 20 | Blaster: 5 | - | - |
| Shotgun Guard | 30 | Shotgun: 24 | - | - |
| Machine Gun Guard | 40 | Machine Gun: 2 | - | - |
| Barracuda Shark | 50 | Bite: 5 | - | - |
| Flyer | 50 | Blaster: 1 | Blade: 5 | - |
| Enforcer | 100 | Chaingun: 3 | Club: 5-9 | - |
| Parasite | 175 | Suck: 25 | - | - |
| Gunner | 175 | Machine Gun: 3 | Grenade L: 40x4 | - |
| Iron Maiden | 175 | Rocket L: 50 | Claw: 10-15 | - |
| Technician | 200 | Blaster: 1 | Claw: 5-10 | Shock: 6-12 |
| Berserker | 240 | Spike: 10-20 | Hammer: 10-20 | - |
| Icarus | 240 | Blaster: 1 | - | - |
| Medic | 300 | Blaster: 2 | Revive | - |
| Mutant | 300 | Pounce: 40-50 | Claw: 10-15 | - |
| Brains | 400 (front), 300 (back) | Tentacles: 10-15 | Arm Hook: 15-20 | - |
| Gladiator | 400 | Railgun: 50 | Clamp: 20-25 | - |
| Tank | 750 | Machine Gun: 20 | Blaster: 30 | Rocket L: 50x3 |
| Tank Commander | 1,000 | Machine Gun: 20 | Blaster: 30 | Rocket L: 50x3 |
| Super Tank | 1,500 | Chaingun: 6 | Rocket L: 50x3 | - |
| Hornet | 2,000 | Twin-Chaingun: 12 | Quad-Rocket: 50x4 | - |
| Jorg | 3,000 | Twin-Chaingun: 12 | BFG: 240+100/sec | - |
| Makron | 3,000 | Light Blaster: 15 | Railgun: 50 | BFG: 240+100/sec |