Yeah, the more I think about it the more I agree RPM is the way to go. It is just too crazy otherwise. Although now I am looking through D&D monsters contemplating all the ways I would torture Nazis with them.
- A skittish invisible Rust Monster. This is not a combat encounter but not immediately obvious why their gear is degrading so fast.
- A Zelekhut. It is a type of Inevitable which are extra-planar constructs. Zelekhuts are charged with hunting down those who would deny justice—especially those who flee to escape punishment.
- All kinds of swarms especially Hellwasps that can crawl inside dead bodies and animate them.
- A pack of Bulette. Literally land sharks.
- A Frost Worm. Bursts out of the ice and swallows someone whole before retreating back under the ice.
- A Will-O-the-Wisp. Leads men to their deaths.
- A group of Dopplegangers. Replacing officers with duplicates.
- A Mimic. When an ordinary trapped treasure chest isn't enough.
- A cluster of Phase Spiders. Won't stay in reality long enough to get shot.
- A Bodak. Sure they might destroy it but do they know that victims killed by its death gaze rise as a new Bodak 24 hours later?
- A swarm of Spectres. Victims slain by a Spectre create a new Spectre in 1d4 turns.
- An Invisible Stalker.
- An Aboleth mage. Slimy fish/amphibian things that can turn people into slaves.
- The Tarrasque. Basically Godzilla.
- A Mind Flayer riding a Beholder. Projects of cone of anti-magic, disintegration beams, mind blasts, and mental domination.
- A Dracolich that is also a high level Evil Cleric. Have fun fighting an actual army of undead.