how he became a raven (who often says "never more" thanks to his name) is never really explained in the plot. However, his sister, Magica states that she needs Scrooge's first dime to make him "duck agian".
He first appears on the tv show Duck Tales. he was voiced by both Terrence McGovern and Frank Welker
He seems to be a version of Ratface who in the Uncle Scrooge comics was Magica's raven.
While this character is more centered in the Tv show "Ducktales" rather than the comics which the show is based on, he appears in one panel of the new
Darkwing Duck series.