“ 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”
“ A rather large armed group slowly walks the road. Unless you get to see what they transport, you could think it is a caravan with expensive goods, or the soldiers escort someone important. But this is a prisoner transport, on the way to mines, criminals on their way for punishment.
The soldiers may be willing to talk, the captain will have a few questions on you and the road, but they will keep distance, and part soon.”
“ An insignficant little species, the candlebug (or waxmoth) is a persistent bane for mages and merchants alike. Each the size of a small digit, these little scarabs thrive on wax and burrow up inside candles, ruining them. Sometimes a late-night worker will hear a crack and a sizzle as his candle expires, only to find the half-burned remains of a waxmoth squirming around on his desk. This is very annoying in worlds where candles are expensive...”