Tanks! Not uncommon today, they were something of a shock when they were first used in WWI. First conceived of in real life AND in fiction in 1903 by HG Well's "Land Ironclads" and French captain Levavasseur, whose project was abandoned 5 years later. In 1911 the Austrians developed two independent designs but both were rejected. In America, the tracked tractor was developed in 1907 by Benjamin Holt, his designs were used as a basis for artillery haulers and supply carriers, thousands were produced. The French investigated the idea of combining a tread or "pedrail" on a cannon carrying vehicle, but the British beat them to the punch, using them in battle for the first time in 1916. Developments in tanks stayed steady but tactics didn't between world wars, until finally the infantry and air supported "Blitzkreig" offensive was developed. Tanks today are centered around a combination of size, firepower, speed, protection in a ratio unreachable in the 1940s. The future tanks however, may evolve from large, tall vehicles that can't traverse some public highways and bridges to low profile, speedy fire support. The US has developed an easily air-transportable big-gunned tank that weighs 30 tons less than the current M1, but even more futuristic is the US Army semi-autonomous unmanned technology demonstrator 'Black Knight'...which may be the next wave of tank technology. Eventually they could be armed with kinetic impact weapons based around an electromagnetic rail gun.
In 1936, HG Wells "Things to Come" showed the development of pre-WWII style tanks to advanced versions of his "land ironclads" Wells Tank.
In literature, the Bolo is a huge, AI driven heavy tank. Hover tanks are a common SF tech...with perhaps SW:The Phantom Menace the most prominent of these to reach the movie screen. In much of anime, tanks have been replaced by "mecha", highly mobile armored suits or robots with tank weaponry and unparalleled maneuverability. In some cases, swarms of robots have replaced the single place tank in land combat. Something the US military is already taking seriously: Swarm