The Mutated Soldiers are minor enemies from Metal Slug 2 and X.
These mutated humans are subjects of the secret experiment of the super-soldier project planned by the Rebel Army. They were sealed together with toxic waste deep in the sewer, until residents up on the ground were disturbed by the foul smell coming out. The Regular Army suspected the complaints of the residents as a sign of the Rebellion's activity and four commandos were sent to investigate.
Deep in the New Godokin City sewer system, it was revealed that the Mutated Soldiers were part of the Super Soldier Project, aiming to create chemicals that could enhance the abilities of a normal soldier. However, the experiment ended in disaster. The soldiers mutated into mindless creatures who then slaughtered all of the Scientists involved. The Rebel Army then tried to seal the mutated soldiers in the sewers.
They are able to crawl on walls and ceilings easily, and can increase their blood pressure, turning their skin red and making them explode shortly after. They will use this explosion attack on whatever approaches their home.
- The Walking Machine vehicle from Metal Slug 4 bears a striking resemblance to the Mutated Soldiers.
- They make a cameo appearance in mission 4 of Metal Slug 4 as statues by the gate to the Zombies route.
- Mutated Soldiers are very similar to the martian Hopper Mecha. Both can crawl along walls and ceilings, and both attack by self-destructing.
- They can be bought in Metal Slug Defense for 50 medals. An unusable variant that crawls on the ceiling appears in the 2015 Halloween Event.