“As Camlan burns in the background, a wounded King Arthur prepares to meet the mounted attack of his hated rival Mordred.” Roger Raupp’s cover for Dragon magazine No 125, September 1987, sets this conflict at a fort on Hadrian’s Wall with 6th century inspiration for armor.
The bleeder resembles the beholder but it attacks with 10 bloodsucking tentacles instead of eyestalks. (Roger Raupp, “Dragon’s Bestiary: Bleeder” created by Ed Greenwood, Dragon No 59, TSR, March 1982) Monsters that resemble other monsters can prey on PCs who are overly familiar with the Monster Manual.
The dancing hut of Baba Yaga is the enchanted home of the most famous witch in Slavic folktales. (Roger Raupp, from the AD&D adventure “The Dancing Hut” by Roger Moore, Dragon magazine No. 83, March 1984.)
“The Norse gods of Gladsheim are fierce warriors often called on by fighters for their aid.” (Roger Raupp illustration from the article “Plane facts on Gladsheim: What it’s like in the land of the Norse gods” by Roger E. Moore, Dragon #90, TSR, October 1984; reprinted in The Art of Dragon Magazine, TSR, 1988.)