What Is No Longer Here
Fellwyr appears in the early registers and nowhere in the modern ones. It was a mid-sized predator that took herds and yard beasts and generally left people alone, recorded season by season through the first centuries — losses tallied, rewards posted, hunts organized across every agricultural ring in the world. Then the entries thin, and stop. The last credited account is nearly three hundred years old.
It is assumed gone, which is not the same as known to be gone. The Frontier is large and mostly unwalked, and a farmer who loses something to a bite that matches nothing he has seen is assumed to be mistaken.
Hidden truth — not known in Teraell
The Fellwyr was an engineered predator built to destroy enemy livestock — the third food-denial weapon beside the Chirska for stores and the Rhydda for standing crops. It was the only one people could fight, because it was the only one that did not fight back. It took three hundred years, and it worked. The Vennek was built to counter two things, and only one survives; its build is more than a Svaekoil needs. The rest of the large predators are gone too — not killed by the engineered ones but out-hunted by them. See Dangerous Fauna and Flora#What they have in common.