He is generally identified with the Swedish king Egil Vendelcrow mentioned in Ynglingatal, Historia Norwegiae and in Ynglinga saga.
[1][2][3][4] The reason why they are thought to have been the same is that each has the same position in the line of Swedish kings and is described as the father of Ohthere and grandfather of Eadgils.
[15] Then, Eofor retaliated by cutting through the Swedish king's shield and through his helmet,[16] giving Ongentheow a death-blow.
En flæmingr farra trjónu jǫtuns eykr á Agli rauð, sás of austmǫrk áðan hafði brúna hǫrg of borinn lengi.
En skíðlauss Skilfinga nið hœfis hjǫrr til hjarta stóð.
[23] The Historia Norwegiæ presents a Latin summary of Ynglingatal, older than Snorri's quotation: Auchun vero genuit Eigil cognomento Vendilcraco, quem proprius servus nomine Tonne regno privavit, et cum domino pedisseqvus VIII civilia bella commisit, in omnibus victoria potitus, in nono tandem devictus occubuit; sed paulo post ipsum regem truculentus taurus confodiens trucidavit.
Cui successit in regnum filius suus Ottarus [...][24] Aukun's son was Egil Vendelkråke, whose own bondman, Tunne, drove him from his kingdom; and though a mere servant he joined in eight civil combats with his master and won supremacy in all of them, but in a ninth he was finally defeated and killed.
Moreover, the sword of the snout can hardly refer to the horns of a bull, but it is more natural to interpret it as the tusks of a boar.
In English, the lines can be translated as but the giant beast coloured its tusk red on Egil.
These kennings, sung originally by Swedes, were later misinterpreted by Norwegians and Icelanders as literal expressions due to the different dialectal meanings of farra.