The PCs discover a large white ball in the branches of a tree, or in a niche in a cave. Unless magically examined, or by a PC with a specialty in insects, it is a plain, smooth white ball. After a short time, it hatches and releases hundreds of spiders, cockroaches, some other nasty bug
A corpse lays at the side of the road, or path. The man has been robbed of everything but a few tattered pieces of clothing. It looks like the scavengers have been working on him for a few days. The smell is ghastly. What dangers lay ahead?
The frozen wastes stretch for miles around. Something waddles through the snow. It's a penguin: An emperor penguin. It waddles slowly, meandering toward the sea. The ranger freezes. "Stay very still," he warns. "Don't move at all." "What is it?" I ask, breathlessly. "It's the most dangerous creature in the whole Yahoo Tundra, and that penguin's about to kick its butt..." (Sorry, Epi! I couldn't resist!)