Fogg is a titular minor antagonist of the reboot TV series, Ben 10. He first appeared in the episode, Fear The Fogg.
Fear The Fogg
When the Rustbucket arrive in the foggy area, it turned out that there is a fog monster, which is destructive. It is first shown with two bright eyes in the fog. When it is fully revealed, it is shown to absorb electricity. Ben transformed into Overflow and he used his water to separate the clouds and Fogg got exposed to the sun and died.
Fogg appeared as a ghost-like fog monster with bright yellow eyes. It also has electricity in its mouth, since it absorbs electricity.
Fogg is a dimwitted monster and only cares about destruction.