Mutant Midget Psychos are stunted psychos, and have exactly the same behavioural traits as their larger cousins. They have much the same appearance as well; shirtless, orange pants and a 'vault mask'. They generally have less health than psychos, but may be more difficult to hit, due to their smaller stature.
Mutant Midget Psychos charge to get into melee range with their intended victims, but are also capable of zig-zagging through terrain to avoid weapon fire. Wielding a "buzz axe", they run up and swing wildly at their target, doing significant damage when they strike. The attack is typically with a double swing pattern, followed by a pause after the second attack. When hurt, Mutant Midget Psychos can flinch, letting a player get a short distance away or counterattack in melee. While only armed with a close combat weapon, they are very capable of throwing axes over long distances, although this attack does minimal damage. Should they sustain significant injury, they are known to cast aside their axes and raise a grenade overhead, then rush their target in a frenzied suicide attack. Killing them at this stage will not stop the grenade from going off.
- Mutant Midget Psychos have different names for each difficulty level:
- Playthrough 1: Mutant Midget Psycho
- Playthrough 2: Freaky Little Maniac
- Playthrough 2 complete: Apeshit Stunted Lunatic