Vampires are human beings that live unnaturally long lives by feeding on the blood of other creatures, typically other people. The vampire has a range of abilities, but is often depicted as being able to change its shape into that of a huge bat, as seen in the novel "Dracula" by Bram Stoker. In this form, the vampire travels by night and stalks its victims. The vampire also has the power to change into a wolf in the novel, and other vampire stories show the monster's ability to transform into mist or dust to escape pursuit.
The werewolf is a human with the uncanny ability to assume the form of a wolf. In some folk stories, this happens only on nights with a full moon, with the human often unable to prevent the transformation from occurring; the werewolf in these stories is depicted as cursed. In other tales, the werewolf can simply choose what form to take at any time. In more modern fiction, werewolves have a vulnerability to silver, and individuals hunting the werewolf typically carry guns loaded with silver bullets.
According to the Crystal Links website, one origin of the werewolf legend lies in Nordic myths, which tell of Ulfhednar, ferocious warriors said to be possessed with the spirit of a wolf.
The werebear is another example of an outwardly normal human being who can transform into an animal, in this case a bear, as a result of contracting a disease or a curse. In the mythology of the "Dungeons and Dragons" game, werebears are generally not evil creatures and are known to aid warriors in bringing other shape-shifters to justice.
The myth of the werebear may have its earliest roots in Greek legends, in the story of Arcas, whose mother Callisto was transformed into a bear by the goddess Hera, as described by the Godchecker website.
The aranea is a giant humpbacked spider that is able to cast magic spells. Through this sorcery, it can transform into the shape of a human being. In spider form, the aranea retains much of its intelligence and possesses arms with hands that enable it to manipulate objects as a human would.