entity_id,period_id,confidence,rationale,source_id,review_status
ENT_NORF_NISSE,PER_NOR_VIKING,high,"The small farm/household guardian spirit (Norwegian/Danish nisse, Swedish tomte/tomtenisse, gardvord), who protects and brings luck to the farmstead in exchange for offerings (porridge with butter) but turns spiteful if neglected; linked to the founding ancestor. Post-medieval Scandinavian folk belief; documented by Simek and Lindow.",SRC_SIMEK_NORTHERN,reviewed