“ A massive iron key - 2' length, 20lbs forged from the bones and horns of demon-lords. When used with a massive portal - carefully built according to documents found in powerful books of evil knowledge, it will open into the realm of demons and allow them to flood into the world. The applications of this item for villains are obvious. Mortals touching this item directly will suffer very dire consequences.”
“ Rather than making a baddy impossible to hit, consider giving it mega-hit points.
Super hard to hit leads to great player frustration. Allowing them to do damage leads to a sense of accomplishment. another variation of this would be to give the bad guy a forcefield that shows damage.You could also give them a mastermind ability that sluffs the damage of to minions who should be easy to kill.Once in a while a super high to hit encounter is ok ,but it should be few and far between.
Your mileage may vary”
“ Idea from the Aeneid. Could make an intriguing encounter when searching for firewood...'Quite near there happened to be a mound of earth, at the highest part of which were growing thickets of cornel and a dense cluster of spiky myrtle-stems. I went up there and tried to wrench the green growth from the ground to provide a leafy covering for our altar. There I was confronted by a horrible and astounding miracle. For from the first bush which I tried to break off...blood oozed in dark drops, fouling the earth with its spots...A piteous moan came from the base of the mound and I heard a human voice answering me: 'Why, Aeneas, must you rend a poor sufferer? I am buried here...for I am Polydorus. Here death overpowered me in a crop of piercing iron-pointed spears. And so a crop resembling javelins has grown over me...''”