Before war famous genetic engineer dr Cornelius Radheart created strange furry blue-skinned creature.
This unnatural animal was designed to deal with nuclear waste.
Dr Radheart was doing some research on it's abilities.
He injected mixture of radioactive isotopes.
And then interesting thing happened...
Several spots on creature's body flashed with bright blue light of Cherenkov radiation.
Subject survived.

Four years later the bombs fell.
Research facility was destroyed and creature escaped.
Soon after dust covered the Sun completelly an temperature dropped uder the scale freezing almost everything.
Survival became hard to achieve by every living theng.
Except dr Radheart's beast.

It doesn't suffer from cold weather.
It can survive long without food.
Radiatian wams the creature up from the inside and fur protects it from the outside.

Wandering through snowy wasteland visiting almost every former hospital, nuclear power plants and landfills, ground zeroes and even secret military facilities.
It's looking for food, and radioactive isotopes attracts this mysterious creature like magnet.
This one-of-a-kind animal is feeling radiation in similar way as we scent smell.

Undangered by nothing this creature will probably live for years, decades, maybe centuries.
No one knows...