here and here. Yrsa is Hrolf's mother.
During Yrsa's crofter upbringing on Als, the diet consists of:
Ran is in the sea;
nicors are in the fen-pools;
the Elmwife brews fog;
drows move at night.
Four great holy times:
Poul Anderson, Hrolf Kraki's Saga (New York, 1973), pp. 67-68.