Lanefan
Victoria Rules
And remember, in 1e the various undead can wreck you in more ways than just by draining levels. Going just from memory:Others have pointed out the potency of energy drain in making early-edition undead absolutely terrifying. I'm not saying D&D should go back to that, but I do like the idea that undead have attacks that rock players back on their heels.
PCs are used to being able to trust that their hit points buffer them from serious harm, and if something bypasses hit points, at least you get a save, and in the worst case a few nights' rest and a little cleric love will put you right. Powerful undead should have abilities that screw you over but good, and your hit points don't protect you, and you don't get a saving throw, and the effect sticks for a good long time--say till the next time you level up.
- ghouls paralyze you (save applies)
- ghasts paralyze you (save applies) and weaken you via their stench (save applies I think)
- shadows hit your strength score for a while (one of the very few RAW 1e creatures that do ability damage)
- mummies rot your limbs away (save applies I think)
- ghosts age you, by a whole bunch
- ghosts also have some sort of magic-jar ability that I've never quite figured out
- coffer corpses (or something similar) can teleport you all to hell and gone, hopelessly splitting the party up in mid-dungeon
- revenants have some nasty ability, as I recall, but I don't remember what it is
- some intelligent undead (vampires, liches, etc.) can also be levelled, and hammer you with class abilities above and beyond what their normal "race" gives them.
Lan-"and there's probably more I've forgtten"-efan