“ Purple deer have begun to appear near the ruins of a fallen city, or other place of power. Hunting the deer is absurdly easy, as their coloration makes them easy to see. The heros prepare a feast from a freshly killed deer find out several hours later that the meat of the new purple deer is poisonous. This can range from cramps and vomiting to the truly sinister and lethal.”
“ The Californian Sea Otter, as a species, eats about 30 different types of food found throughout its range. Each individual otter, however, will only eat 3 or 4 of these foods - those it was fed by its mother as a child. It will not eat the others even if failure to do so means it would starve. Maybe other, possibly larger and more dangerous creatures and monsters, have similar habits.”