Feyr
In the Dungeons & Dragons fantasy role-playing game, the Feyr, or Fihyr (pronounced "fear") is a fictional monster formed when residual magical energies combine with ordinary nightmares. In appearance it resembles a large human brain with a partial layer of skin streched over it, with many tentacles for walking and grabbing at unwary travellers. The "face" of the Feyr is a seemingly random collection of large, golden eyes and mouths filled with sharp, needle-like teeth. Owing to their conception, feyrs are found most commonly in places where large numbers of magic-users gather, such as cities.
Most Feyrs do not last beyond the night of their creation, since they die instantly when exposed to sunlight, but larger versions of the creature known as "Great Feyrs" are immune to the effects of sunlight. Great Feyrs still despise sunlight, though, and mainly come out at night, preferring to lay low in secluded spots during the day.