Nightmare Fuel / Dungeons & Dragons (1983)

• Venger, with his deep, booming Peter Cullen voice, his fangs, pale deathly pallor, horn, and wings, is also trying to kill a bunch of kids, and can assume some very convincing disguises in his efforts to do so. Anyone you meet in the Realm could be Venger leading you into a death trap.
• The idea that you could get stuck in The Realm just because you decided to ride a roller coaster at an amusement park. And our group isn't the only ones to arrive that way. You'd think they'd shut the ride down after the first few kids go missing...
  • It's implied that Year Inside, Hour Outside is in play, so maybe no one is actually missing yet.
• An episode where the villain caused interdimensional portals to appear under kids' beds and his minions dragged them through to perform slave labor for him — complete with terrified parents trying to keep their kid from disappearing through the rift. On the other hand, when Bobby, the youngest of the featured characters, is snatched, the other kids and their new ally force the portal open and dive in after the kidnapper with a determined look that promises a world of hurt for anyone who tries to stand in their way.
• One of the characters got turned into a bogbeast. Eric must've failed his saving throw against Polymorph.
• The fun moment in "Quest of the Skeleton Warrior" when Venger tried to turn Hank into one; before the process is interrupted, the ranger's entire outer meat layer starts to melt off.
• The kids once accidentally summoned Venger's master, which manifests as the top half of a giant green face with slit-pupil eyes above the cloud layer, and as a cyclone of absolute hellfire from there to the ground. Might not look so threatening in a cartoon, but imagine seeing something like that yourself and doing anything other than crapping your pants and curling up into a whimpering ball. Now imagine that it's following you, and can appear anywhere in the world within seconds, and you've got a taste of what Dungeon Master and the kids went through.
• The series was pretty dark for a childrens' cartoon in The '80s, which didn't do it any favors with the syndication censors. "The Hall of Bones" was one of the better episodes... but featured a were-spider transforming on screen and the titular haunted hall, so it didn't air often.