6. Charlie
Charlie is the orphan Bart 'adopts' in the 2009 episode 'O Brother, Where Bart Thou?" After becoming upset that he doesn't have a brother and "just two sisters", Bart tries to persuade Homer and Marge to have another baby, even tampering with Marge's birth control pills, which has hilarious effects on Nelson. Upon realising his parents don't want another kid, Bart decides to adopt one, though is told "a ten-year-old can't adopt". After seeing Bart leave the orphanage, however, Charlie tracks him down and becomes his new brother. The two become close, and get up to mischief together, but Charlie is later adopted for real by a family with six girls, and is driven away in the back of a van screaming, never to be seen again.