In the Resident Evil franchise, the term "Irregular Mutants" refers to creatures created unintentionally via viral outbreaks and other such incidents, as opposed to B.O.W.'s which were created on purpose under controlled circumstances. An example of an irregular mutant is Lisa Trevor, a girl used by Umbrella as a test subject for multiple viral experiments. Below is a list of all irregular mutants that have appeared throughout Resident Evil's expansive universe.

List of irregular mutants