These monsters are born human, but by mutation later in life suddenly take on a craving for human flesh. The mutation is transmitted by a gene linked to the Y chromosome, therefore only affects males, and is expressed after puberty. The longer they ignore the urge to cannibalize the living, the deeper into madness they descend until the urges can no longer be controlled. Those that succumb to their cravings before madness sets in retain their sanity, knowledge, and identity. However, like an addict, they always fall prey to their own cannibalistic natures. They frequently prey on those that will not be missed, the homeless, degenerate, and orphaned. In addition to hyper-animalistic aggression and territorialism, rougarou feel the intense desire to reproduce, likely due to the fact that the recessive gene needs a specific, and rare, pattern of recombination to surface in another human.