
Black Fog
Black Fog is an giant alternate version of Haunter which appears once in the manga, and once in the anime main series (where it is referred to as Ghost), as well as in Generations.
Biology
Physiology
Black Fog appears as a Giant Haunter, in the manga it appears with a much spikier appearance than regular Haunter and it's claws and teeth appear sharper. In the anime it has red glowing eyes.
Natural abilities
As stated in the Electric Tale of Pikachu, Black Fog are able to consume an enemies soul, they are much stronger than Gastly, Haunter, or Gengar and has the power to control other Ghost-types.
Anime
Main series

Ghost in the anime
A Giant Haunter, which only referred to itself as Ghost (Haunter's Japanese name), appeared in Fear Factor Phony, Haunter transformed into this form by merging with several other Ghost-types, including two Gastly, two Duskull, and a Shuppet.
Generations

The giant Haunter chases Cheryl and her Chansey
In The Old Chateau, a giant Haunter appeared in the Old Chateau after the butler's ghost disappeared, appearing from a massive cloud of darkness and lightning, it chased Cheryl and her Chansey, and apparently consumed them. However they soon woke up elsewhere, wondering what happened.
Manga
Electric Tale of Pikachu
- Main article: Black Fog (ETP)
Black Fog makes it's debut in the Electric Tale of Pikachu, it appears as a Legendary Pokémon that was worshiped in ancient times. Black Fog killed many of the humans and Pokémon living in Lavender town until Ash came to capture it, it self destructed to avoid capture.