Short answers, pulled from the story.
Krákumál is a 12th-century skaldic poem consisting of a monologue by Ragnar Lodbrok, spoken as he is dying in Ælla's snake pit. The poem runs to 29 stanzas and recounts the joys of his warrior life, his hope for revenge, and his expectation of reaching Valhalla.
Krákumál was composed in the 12th century, almost certainly in the Scottish islands. It is written in a form of háttlausa, a style without regular end-rhyme, and consists of 29 stanzas, most of them with ten lines.
Thomas Percy was the first to translate Krákumál into English.
In the episode "All His Angels", Krákumál forms the basis for the final words of Ragnar Lothbrok, played by Travis Fimmel. In a separate episode, "The Best Laid Plans", Stanza 23 of the poem is read aloud in Old Norse.
French Nordic neofolk group SKÁLD performed extracts from Krákumál in their song Krákumál, featured on their 2019 album Vikings Chant.
Krákumál deals with the joys of a warrior's life, the hope that Ragnar's death will be followed by violent revenge, and the certainty that he will soon experience the pleasures of Valhalla. The poem presents death not as defeat but as the final proof of a heroic existence.