The Mule is a Maibatsu box truck and one of the series' longest-running commercial vehicles, having featured in nearly every entry since Grand Theft Auto III; it is due to return in Grand Theft Auto VI. Its classic incarnation changed little between GTA III and Vice City Stories, where it closely resembled a late-1980s Ford E-350 cube van.
Vehicle data via GTA Wiki (Fandom), CC BY-SA 3.0.