A magical phenomenon can be found on rare occasions in Alyth Den and doubtless other places on the Cateran trail. Called ‘ice wool’ or ‘hair ice’ it appears on freezing cold yet humid days. Long, silky white hairs grow from the bark of broadleaf twigs and small branches.

Also called ‘frost beard’, it is not hard to see how legends of bearded hobgoblins came about. It is in fact created by the fungus Exidiopsis effusa by a little known mechanism. Once produced, the fine hairs are stabilised and prevented from recrystallising by antifreeze proteins.