Snorri Sturluson states in his Gylfaginning (34) that "Loki's brothers are Býleistr and Helblindi", and several Eddic texts use the Loki-kenning "brother of Býleistr" (bróðir Býleists) (Völuspá, 51; Hyndluljóð, 40; Skáldskaparmál, 16).
However, in the poem Hyndluljóð (Lay of Hyndla) the nine giantess mothers of Heimdall have different names including Gjálp and Greip and Járnsaxa which are known from other myths and are not specifically mentioned as sisters in the poem.