Fog is one of many abilities possessed by vampires in the novels series to generate dense fog that can hide them. It is a power that can only be used by vampires of great power and age and it is usually used to to distract their victims before the kill.
In the novels, Damon Fransesco Salvatore and Katherine von Swartzschild can manipulate the weather. One of the derivatives of this power is fog. This disturbance may be used primarily to cover the vampire attacks and cause confusion. Katherine consistently used the fog to cause fear, panic and confusion, as well as clear evidence of her arrival in Fell's Church. Elena, Stefan and Damon were victims of fog during their battle against Katherine.
"But suddenly her head was reeling; it was full of gray and spinning fog and she couldn't hold on to Stefan. She couldn't think; she couldn't speak. The floor seemed to be dropping away from her. Dimly, she realized that Power was being used against her, that it was overwhelming her mind. She felt Stefan's body giving, slumping, falling away from her, and she could no longer resist the fog. She fell forever and never knew when she hit the ground."
"Elena moaned and almost surfaced from unconsciousness, but the gray fog dragged her back under before she could open her eyes. Her thoughts seethed around her again."
Both in books and in the series, the fog is known to cause fear, confusion and disorientation. However, the fog in the series is light and thin. In the books, the fog is described as sensory deprivation and a combination of illusion and real fog as well as it is much more dense and can be used against any being.
During the first episodes of Season One, Damon Salvatore can manipulate the fog. In the Pilot, Damon used the fog to kill a couple. During a visit of Elena Gilbert to the cemetery, Damon used a crow and the fog to scare Elena, finally, the fog appears when Vicki Donovan is alone in the woods and that's when Damon attacks. The next episodes happens the same, the fog appears and the people die. The Fog is no longer used in The Vampire Diaries because it was thought to be too supernatural.
- Fog and Mist are commonly confused. The main difference is density. Fog is more dense, causing that you cannot see anything.
- The fog was removed as the power of the vampires in the series, because it was considered too supernatural.
- In the Facebook game fog plays an important part. You have to clean the fog in order to collect new items.