The authors of Mediaeval bestiaries were not merely concerned with providing a description of creatures. No, for them, everything in Creation had a purpose - nothing had been made without an ulterior aim: the edification and instruction of sinful man. So, each creature described is not merely an animal but a living parable, imbued with moral or religious symbolism.
When the great ice-sheets covered the north, life retreated before them, but some species stayed and endured. Whilst man huddled around fires in his caves, mighty beasts roamed the tundra: the Woolly Mammoth, the Woolly Rhinoceros…and the Woolly Wyvern.
Small red flower, originally sprouted from the blood where St. Senren fell but now found widely over all Laurentia. Occasionally, a rare white flower will be found, with powerful magic properties. It is particularly prized by the religious order, the Senrenites.
The village sits on the edge of the deep fjord, often engulfed in mist or rain. Its people are fishermen, who work even through the sea-ravaging winter. And they pray to the gods of the deep.
At the beginning of every winter they hold a summoning ceremony. Three boats are taken out into the fjord, a hornsman on each. The mournful horns are blown in the language of the whales, the gods of the deep. The whales sometimes appear in answer to these calls, and it is taken as a good omen when they do.
To a party of PCs wandering the misty hills and valleys nearby however, the doleful whalesong of the horns can be disturbing and misinterpreted...