“ 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”
“ Whale's Jaw is a crumbling stone monument that was once in the form of a skeletal whale. Many years have past since the construction of Whale's Jaw and these days all that can be seen in the 'jaw' jutting from the earth as if it is yearning for a final glimpse of sunlight before taking a plunge into the earth.
All around The Jaw are remains of oddly formed and weathered structures. They seem to have been smoothed and tumbled by severe rain or ocean currents. <em>Most say it is just another Wonder of The World, a mystery we will never know the answer to, but some know differently... I know differently...</em>”
“ The PCs are exploring the catacombs beneath a Colosseum-in-Rome type of structure, when they come across a foul-smelling, stagnant, ankle-deep with algae, public mass latrine. Countless urinals of marble, line this rather large chamber equally crafted of marble. Whatever system of plumbing once worked here, has not in many years. Old graffiti lines the stained,dirty walls, prominently bolded are such intellectual poetic musings as, 'Urine For It Now', 'I Pee Therefore It Comes' and 'Now Urine Trouble'.
A few moments after the PCs get to take in this unpleasant location, they hear the low rumbling of ancient plumbing and rather large Urine Elemental rises like a great, wet, wave of filth to attack them. The creature reeks and exudes noxious debilitating fumes, while its liquid strikes burn flesh like acid.”