Warning: The following contains SPOILERS for the Superman and Lois season 3 premiere.The premiere episode of Superman and Lois season 3 featured the surprising appearance of the Green Arrow villain Onomatopoeia, who never appeared on Arrow or in any Arrowverse series. Superman and Lois season 3 already promised to be full of villains, featuring its versions of popular Superman adversaries Lex Luthor and Intergang leader Bruno Mannheim. This made the introduction of Onomatopoeia all the more surprising, particularly given the way the character was changed from the comics to make them a more formidable threat.
https://screenrant.com/superman-lois-green-arrow-villain-arrowverse/