Skinwalkers

"The family dog seriously needs a neuter. They can change anywhere, anytime. Skinwalkers infect you with a single bite. Otherwise, they're basically a werewolf cousin -- silver will drop them, they chew hearts like sausages."

- Sam Winchester, about Skinwalkers

Skinwalkers are supernatural dog-like creatures that were encountered by the Winchester Brothers and other Hunters. Dean Winchester, after reading John Winchester's journal, sees them as cousins of werewolves due to their similarities; much like them, skinwalkers can transform into animals.

All skinwalkers originate from the Alpha Skinwalker. This Alpha placed thirty skinwalkers in dog form with families. He planned to create an army of skinwalkers by turning the families in skinwalkers all at once, turning 30 into 150.

Characteristics
Skinwalkers are considered by hunters to be werewolf cousins because they have similar characteristics. They shape shift into an animal, they are killed by silver weapons, they infect people with a single bite, and they feed on human hearts.

Unlike werewolves, skinwalkers' transformation into a canine is complete and they are not limited by the phases of the moon. Skinwalkers can change into their animal form at any time, day or night. Skinwalkers also mostly change into canines instead of a wolf-human hybrid like werewolves. Like other creatures such as vampires, and real canines, they seem to have a pack mentality, as they are led by a pack leader, who in turn answers to the Alpha Skinwalker.

Other common features similar to werewolves is the fact that they always eat the heart of their victim and they have an infectious bite, they can turn humans into skinwalkers simply by biting them and passing on the infection to the person. Silver has been shown to be the only thing that can kill a skinwalker. Whenever a skinwalker is killed by a silver bullet or knife in its animal form, it reverts back to its human form.

Powers and Abilities

 * Enhanced Strength - Their strength seems to be greater than the average human's, as in its dog form it was able to kill humans. Their strength appears to increase with rank (much like vampires), as the Pack Leader was able to beat Lucky around with no difficulties. It seems that it's only in their canine form that they possess their strength, as when confronted by Sam, Lucky chose to run rather than fight.
 * Super Speed - Skinwalkers, in their animal form, can run and move faster than humans.
 * Accelerated Healing - They appear to be able to heal themselves much faster than humans. A skinwalker was hit by a minivan, but when he returned back to his human form he appeared to have no physical harm. The same skinwalker was shot with a bullet later, but the wound healed extremely quickly.
 * Invulnerability - Like many other shapeshifters, Skinwalkers can only be killed by silver bullets to the heart or head. They can, however, be injured.
 * Super senses - They can smell far better than humans, in either form. Using this ability, they can tell if they are being followed or if someone is in the vicinity, within an approximate range of 100 yards or more. Also, a skinwalker's hearing is comparable to that of a dog.
 * Infectious bite - Like Werewolves, Skinwalkers possess a poisonous bite; if someone is bitten by a Skinwalker, he or she will also become a Skinwalker.
 * Shape-shifting - Like Werewolves, Skinwalkers possess the ability to transform into canines. Unlike werewolves, however, skinwalkers transform completely into an animal rather than a hybrid man/wolf creature. Skinwalkers can change from their human to animal forms anytime without a full moon.
 * super agility

Vulnerabilities

 * Silver - Like all other shapeshifters, Skinwalkers are vulnerable to and can only be killed by weapons made of silver. Either a silver bullet or knife in its heart or head will kill it.
 * Significant damage - Apparently they can die, if significant damage has been caused, as when the Pack Leader's Right hand tried to rip Lucky apart.
 * The Colt - Since this gun can kill almost anything, it can possibly kill Skinwalkers.

Season 6
Crowley wants Sam and Dean to capture another Alpha for him, and he puts them on the trail of deaths he thinks may be linked to the Alpha Werewolf. Finding that Cal Garrigan is a common link between the victims, Sam and Dean suspect that he is a werewolf until he, too, is killed. Cal's girlfriend, Mandy, becomes their next suspect until Sam witnesses the woman's dog, Lucky, change into a man. It seems that Lucky has been killing anyone who threatens Mandy or her son.

Sam chases him, but the man (in dog form) is hit by a car. Sam and Dean take Lucky from the vet hospital, bind him in rope and silver chains to restrain him, and interrogate him. It transpires that the man was homeless when he was approached and recruited to become a skinwalker; he was told that being bitten would make him strong and fast. Lucky then reveals that he knows of about 30 skinwalkers who have been recruited and are living with families as pets. On a signal from their pack leader, they are supposed to infect their families, thus recruiting more skinwalkers. He tells Sam and Dean that there are packs in many towns, but he knows nothing of the Alpha Skinwalker.

Lucky leads Sam and Dean to the Pack Leader, but he has kidnapped Mandy and her son and threatens to kill them unless Lucky turns them. Sam and Dean attack, and all the Skinwalkers are killed except Lucky, who escapes despite being shot with a Silver bullet. Lucky, in human form, then goes to visit Mandy and tell her how much he appreciated her kindness, but she tells him to leave. Lucky transforms into a dog and dejectedly leaves.

Appearances

 * Season 1
 * Wendigo (mentioned)
 * Skin (mentioned)
 * Season 2
 * Heart (mentioned)
 * Season 6
 * All Dogs Go To Heaven
 * Season 9
 * Dog Dean Afternoon (mentioned)

Known Skinwalkers

 * Alpha Skinwalker
 * Pack Leader (deceased)
 * Lucky

Trivia
Skinwalker
 * They appeared in the series, as monsters of the week in Season 6 episode All Dogs Go To Heaven.
 * Skinwalkers are the suspected culprits in Season 1 episode Wendigo and Skin, but turn out to be a Wendigo and a Shapeshifter, respectively.
 * Skin-walkers appear often in Native American mythology. They are said to be people with the ability to turn into any animal they desire (although wolves, bears and ravens are more commonly mentioned).
 * Acoording to Co -executive proudure Adam Glass in "Suerpnatural The Official Companion Season 6", Skinwalker's don't just take the form of a canine, they can take any animal form they want and People can summon the Alpha Skinwalker to bite them and turn them into a skinwalker by using a native american summoning ritual. Adam Glass also revels that The Alpha Skinwalkers plans were for Skinwalker to pass as house pets were not limited to just dogs, but as cats, rabbits, hamsters, parakeets, even turtles and turn their owners into skinwalkers as well.