Tom Sawyer

Tom Sawyer turns up in Futurama's future as a small, cheerfully anachronistic presence rather than a book character with a river and a fence — a knowing wink at Twain's mischievous boy, dropped into the show's world of robots and future-tech for one quick, gag-driven appearance.

He works because Tress MacNeille, one of Futurama's great utility voices, can drop a character like this in fully formed with just a few lines — catching the plucky, sly cadence audiences already associate with Tom Sawyer and using it purely for a fast, well-aimed joke rather than any larger arc.