Blake McIver Ewing (born March 27, 1985), also known as Blake McIver, is an American actor and singer. He was known for playing Michelle's friend Derek on the sitcom Full House. Ewing also portrayed the role of Waldo in the 1994 feature film version of The Little Rascals, and voiced Eugene on Hey Arnold!. He is known for playing wealthy, snobby, arrogant and elitist characters.