Movie monsters as they began their rise in the 1930s and 1940s gave them the typical weaknesses that everybody on the today’s street can recite. Vampires, werewolves, and zombies tended to stay the same way including the 1950s-1970s. However, in the mid-1980s started a new trend of monster weaknesses and initial transformations, the growing spread of blood contact tended to mirror the real world fears of actual diseases. Unfortunately, mummies are going to be left out of this because once one is cursed to protect a sacred object for eternity or waiting for one’s love re-animated love to be set on fire to stop one doesn’t sound quite so medically composed.
The night-stalkers costumed in Victorian-styled garb with elongated fangs beside dental cleaning bills need plenty of weaknesses. Dracula was cursed to immortality by love. Garlic, sunlight (UV light), Holy Water, fire, heart-staking, and decapitation were some of the more common weaknesses. From the 1980s on vampirism is shown more virally: Near Dark, Ultraviolet, Day Breakers, etc…Vampirism is shown more from genetics or bad family relations from Blade, Blood Rayne, etc…With vampires described as drinking blood, good blood is shown as far better than some kind of diseased blood which could be thought of as a vampiric bio-necro weapon of choice.
The lycanthropically empowered may have the perfect reason to shave their legs. The Wolfman and most other movies had the full moon or extreme anger (furry little wolf hulks) for the reasons for transformations. Silver and wolfsbane are the weaknesses from Gypsy legend to current times. American Werewolf and the Howling didn’t change them. Ginger Snaps had wolfsbane converted into some liquefiable temporary cure. The spread of werewolf is being bitten by human that almost always kills the wolf in the attack. One might compare a rabid dog almost as starting point for a wolf creature attacking feverishly anyone.
The growing popularity of zombies is almost inversely proportional to the consistency of their rotting flesh. First zombies were practically tied to voodoo and the powder that turned people into plantation workers according to White Zombie and the Serpent and the Rainbow. The bio-impaired (if that the politically correct for zombie?) spread from biting victims which soon turn and continue the chain of progression. The late 1960s saw George Romero start to fuse zombies with ghouls for carnivorous attitudes for Night of the Living Dead and his following films. Return of the Living Dead had tanks of some type of gas and barreled zombies. The Resident Evil movies had the entire bio-weapon accident for the start which jumps pretty quickly to the once bitten will be zombified. Most of these movies have the only one way to stop zombies: brain dismemberment and body destruction.