A red cap or redcap, also known as a powrie or dunter, is a type of malevolent, murderous dwarf, goblin, elf or fairy found in Border Folklore. They are said to inhabit ruined castles found along the border between England and Scotland. Redcaps are said to murder travellers who stray into their homes and dye their hats with their victims' blood (from which they get their name). Redcaps must kill regularly, for if the blood staining their hats dries out, they die. Redcaps are very fast in spite of the heavy iron pikes they wield and the iron-shod boots they wear. Outrunning a redcap is supposedly impossible.
They are depicted as sturdy old men with red eyes, taloned hands and large teeth, wearing a red cap and bearing a pikestaff in the left hand.
The tale of one in Perthshire depicts him as more benign; living in a room in Grantully Castle, he bestows good fortune on those who see or hear him.
Robin Redcap and William de Soulis
The redcap familiar of Lord William de Soulis, called "Robin Redcap", is said to have wrought much harm and ruin in the lands of his master's dwelling, Hermitage Castle. Ultimately, William was (according to legend) taken to the Ninestane Rig, a circle of stones by the castle, then wrapped in lead and boiled to death. In reality, William De Soulis was imprisoned in Dumbarton castle and died there, following his confessed complicity in the conspiracy against Robert the Bruce in 1320.
- Red caps are mentioned by Hermione Granger in Harry Potter and the Prisoner of Azkaban by J. K. Rowling, also appearing in the eponymous video game.
- Redcap is a mob genus found within the Dark Age of Camelot Midgard realm.
- In the video game "Fable Legends", there is an enemy creature named the Redcap. Instead of dyeing its hat with the blood of victims, it is dyed with their own, through the nails that they hammer into each other's skulls.
- In the Dresden Files novel "Cold Days" by Jim Butcher, The Redcap is a vassal of Maeve (The Winter Lady) and a major antagonist in the story. The Dresden Files: The Redcap
- In the Harmatia Cycle book "The Sons of Thestian" by M.E. Vaughan, the Prince Jionathan fights a Red Cap in a Korrigans' nest.