Devan and Quenley Woosterfield are Simon's half-older brothers and the main antagonists of the The Simpsons episode Double, Double, Boy in Trouble. Them were always trying to kill him to get the family fortune.
Both are voiced by Tress MacNeille
When Bart Simpson switched places with Simon and was almost killed at a ski resort by sliding down an expert track, Devan and Quenley thought he was dead and Quenley may have poisoned Devan with a potato when he mentioned splitting the money fifty-fifty, which Devan seemed to eye the potato suspiciously when she offered it. Milhouse seemed attracted to Devan when he met him.