Fenris is one of the deadliest worlds in the Imperium. Its weather is infamous: winters are cold and icy; the brief summers are almost intolerably hot. However, once every few years or so comes the season known as Helwinter. The planet's long orbit takes it far from the sun, and it becomes cold for many standard years. At the same time the planet passes through a swarm of meteors that bombard its surface like a rain of bombs. The contrails of the descending meteorites fill the night skies, and the impacts cause the earth to shake like a frightened beast.
During this period the tribes of Fenris take to their ships and seach the icy seas for places of safety. Loading all their possessions onto their longships they navigate through the icebergs in search of safety. Some make their homes on the very surface of these floating islands of ice. Others are lost to the mighty tidal waves caused by the impact of meteors. Many more will die when attacked by ice whales and kraken.
Kraken are the most tterrifying monsters of the deep. They come to the surface only during Helwinter which is just as well, for a full grown kraken can measure as much as five miles long with tentacles that drag a full twenty miles. Normally they dwell only in the deepest of ocean trenches but the tectonic shifts caused by the constant meteor impacts disturb them and cause them to rise.
One of the most ancient tales of Russ tells of how he went fishing one day and caught the Father of Kraken, the legendary monster whose tentacles girdle the world and hold entire continents in their grip. Russ is said to have pulled the monster from the sea lifting it by its tentacles. When his awed comrades shuddered in terror, Russ declared that it was too small and threw it back, declaring he would return later when the tiddler was full grown.
Imperial scholars think that this story is mere legend but with a core of truth. Russ may have encountered a kraken and killed one. It would not have been beyond the power of a Primarch such as he. Indeed, this kraken may be the source of the so-called kraken's egg, a giant leathery piece of flesh more than fifty foot across that lies within the Trophy Room of The Fang.