“Look out everybody, things are about to get awesome!”
Lab Rats don't pick up loot or items on the ground, and attack mainly from close range. The only time a Lab Rat will attack from a range is when he cannot reach a target and at that point will begin to toss a buzz axe in a manner similar to a regular Psycho. If they get close to their target, they will unleash a devastating eye-laser attack that can quickly destroy shields and wearers alike. As they advance towards their target, they will cover their face with their non-mutated left arm, making it harder to score a critical hit. Shotguns are effective in hitting their head even if blocked by their hands thanks to the pellet spread.
- Unlike most other types of rats wearing gas masks, Lab Rats wear surgical masks.
- In True Vault Hunter Mode they are renamed R.O.U.S, and in Ultimate Vault Hunter Mode they are renamed Mutated Lab Rat
- R.O.U.S is an acronym for Rodents Of Unusual Size. This is a reference to the strange rats that inhabit the fire swamp in the 1973 novel and 1987 movie The Princess Bride.