Turns any living things in the world into a purple, furry, indestructible killing machine.
The PX-41 is a very dangerous mutator engineered in the top secret PX-Labs, located in the Arctic Circle. It is capable of turning any living things in the world into a purple, furry, indestructible, mindless, killing machine that is so dangerous that it can destroy anything in its path. The effects of the serum can be counteracted by PX-41 Antidote, an antidote serum that was invented by Dr. Nefario.
- It is unknown what happened with the rabbit that was mutated into a purple monster rabbit and the three kittens in the mailroom of Gru's that is mutated to purple kittens.
- The only two ways to turn into a purple monster is to inject it or drink it.
- The serum can turn the one who drank it or injected it big or like the Evil Minions, long arms and bushy hair.
- Despite turning anyone or thing it is injected or swallowed into a mass of destruction, a PX-41 mutated subject is not completely indestructible, in fact, as shown in Despicable Me 2, PX-41 Mutated subjects have three major weaknesses:
- High-pitched noise. As shown by a evil Kevin, PX-41 subjects are weak to high-pitched noise such as Agnes's scream. When she unleashed it when evil Kevin was about to eat her unicorn doll, Kevin was in obvious pain and was dazed and confused for several seconds afterwards, allowing Margo and Agnes to escape.
- Shown by a mutated El-Macho, a concussive electric shock can knock a PX-41 subject out, such as (Lucy's) lipstick taser fired by Gru. Although a mutated subject recovers much faster than regular humans (Gru after being zapped).
- Again, as demonstrated by a mutated El-Macho, a PX-41 subject can be completely knocked unconscious by Dr. Nefario's Fart Gun due to the fact not only their muscle, size and aggression are increased during the mutation, but also their sense of smell since when Gru gave Nefario a "21-fart gun salute" (actually, 22), the noxious cloud only cause Gru and Nefario to cough while a single fart cloud completely knocked out a mutated El-Macho.
- As shown in El Macho's lair, a certain type of metal (El Macho used it to make the cages holding the Evil Minions) can hold and prevent mutated subjects (at least Evil Minions) from escaping. It is not known what material can withstand the fierce bite from Evil Minions.