Werepanthers are a supernatural species that endows individuals with the ability to physically assume two different forms: human and panther. They are a branch of the Were- variety, which includes werewolves and shapeshifters. Unlike vampires, on the HBO original series True Blood, the existence of werepanthers is not public knowledge.
According to their mythology, panthers once ruled the animal kingdom. Humans worshiped panthers as gods, until the "Sky People" turned all humans against nature. The only people who refused were a woman called Ghost Mama and a man called Ghost Daddy. One night, under a full moon, they went to the leader of the panthers and told him that they did not want to live as humans anymore, and asked to become panthers themselves. The leader then ate Ghost Mama and Ghost Daddy, who absorbed the panther's magic while inside its stomach. The leader then vomited Ghost Mama and Ghost Daddy, who became werepanthers during the next full moon, and thus the progenitors of the species. ("If You Love Me, Why Am I Dyin'?")
The only werepanthers that have been featured on the show all belong to a dirt-poor extended family called the Norrises. Werepanthers are an endangered species, and the Norrises have resorted to inbreeding in order to keep from going extinct. However, this tactic has essentially backfired on them; because of the lack of genetic diversity among them, the family is ravaged by feeble-mindedness and congenital illnesses which result in sterility and high infant mortality. It is unknown if the Norrises are the last of their kind.
As with all Weres, werepanthers can shift from their animal form to human form at will, except during the nights of the full moon. In the Were hierarchy, they are considered to be the lowest on the totem pole. Due to several generations of inbreeding, they have been rendered much weaker than werewolves, and are exceptionally feeble-minded. Biologically and socially, they are practically indistinguishable from regular humans, except for their distasteful practice of incest. They are not immortal, and their rate of aging and expected life span is the same as humans. They have the same needs and weaknesses as humans. As with all Weres, the Panther is hereditary. An individual must be born a werepanther, inheriting his or her status from one or both parents. They are able to reproduce with humans and other Weres; the species of the offspring of these disparate couplings occurs randomly. For this reason, the Norrises are unwilling to procreate with humans or other Weres. Werepanthers are not born with the ability to shift; this generally occurs spontaneously at some point in their youth.
- In the show, the trainers use melanistic leopards (Panthera pardus) as cougars (Puma concolor) have not been documented exhibiting a melanistic variant.
- In the books, a werepanther is much stronger than a werewolf. In fact, they were on par strength-wise with an average aged Vampire.
- Jason becomes a werepanther in the book.