Bukalla was a legendary Fremennik hero, who died after a brutal battle with Dagannoth Supreme, according to the Epic of Bukalla. He was the wielder of the Balmung, which was a huge dagannoth-slaying sword. Kharshai later named his dagannoth-tuned bane greataxe Balmung in honour of Bukalla.
Dagannoth Supreme's examine text was the first place Bukalla was mentioned. The dialogue with the boss pet Supreme hatchling also mentions Bukalla, stating the Bukalla's bones were tasty, and he ate all of them, with there being none left.