"I grandly decided to ape the structure and ironic style of Byron's masterpiece Don Juan"

The Byronic stanza predates Byron by a few hundred years. It is described in the Penguin Dictionary of Literary Terms as 'An eight-line iambic stanza ryhming abababcc'. As fashioned by Byron, the ottava rima uses the rhyming couplet at the end of each stanza as a kind of comic flourish.