Ronald Reagan's Head

Preserved as a disembodied head in a jar in the 31st century, this relic of the 20th century turns up in the background of Futurama's world as a piece of political furniture — sometimes literally a head of state, sometimes just a museum curiosity. He speaks with the same folksy, genial authority his era remembers, entirely unbothered by his reduced circumstances.

The joke is the flat, matter-of-fact way the show treats a preserved president's head as an unremarkable civic fixture, and Maurice LaMarche's uncannily warm impression sells the absurdity straight rather than mugging for it. It's a one-note gag that stays funny precisely because nobody in-universe finds it strange.