Farderek is a leprechaun seen in the episode Luck o' the Ducks.
Farderek has been mentioned to be a liar by his own ruler. Despite this, he does grant Scrooge his wish.
Farderek was trapped in a shipment that Scrooge receives. When let out, he leaps into Scrooge's Money Bin by mistake, and takes $200.26 of the money away with him. He escapes into Duckburg, only to get into trouble whilst there. Scrooge saves his life, though Webby begs her uncle not to hurt him. The leprechaun introduces himself to Webby, and they return to McDuck Manor for some food. Scrooge manages to get Farderek to admit that saving his life entitles him to a wish of his choice. Scrooge decides to head off to the Emerald Isles, where he ultimately asks for the leprechaun treasure. Farderek's ruler is furious, and tells him to make sure that Scrooge never returns from there.
Although Farderek sets up a trap, after Webby once again shows him kindness, he tells her the truth, and together they stop Scrooge from becoming trapped. At the end, Scrooge decides to grant Webby one wish in return, and she requests that Farderek come over for tea.