It's most likely the name of a future Ford Bronco model.
Ford just filed to trademark the name "Warthog" in the US market, as it applies to "land motor vehicles, namely, passenger automobiles, pick-up trucks, sport utility vehicles," and the move could point to a new model within the Ford Bronco lineup.
To be clear, nowhere in Ford's filing does it say anything about the Ford Bronco at all; the automaker could be reserving the "Warthog" name for any number of different things. But as of right now, a new Bronco variant is our best guess for what Ford has in store, mostly because the folks at RevMatchTV reported on just such a model back in July, before the 2021 Ford Bronco's official reveal and long before Ford filed for this trademark.
In the report, RevMatchTV suggested that the "Warthog" name would stand in for the legendary "Raptor" off-road moniker on the new Ford Bronco, even though they would be comparable models. The Bronco Warthog will reportedly pack a twin-turbocharged 3.0L gas V6 like the one in the performance-oriented Ford Explorer ST, which is rated at 400 peak horsepower and 415 lb-ft of torque.
Of course, since then, new evidence has emerged that points to a hardcore Bronco model that will actually wear the Raptor nameplate, casting more uncertainty on the report. But at the very least, a Bronco variant appears to be a likely destination for the Warthog moniker.
Of course, just because Ford has filed for a trademark does not necessarily mean that the automaker will use it. Companies routinely file for intellectual property preemptively to prevent other automakers from swooping in and using trademarks, logos, and inventions they might want the option of utilizing.
If there is a Ford Bronco Warthog/Raptor in the works, it's not expected to arrive until 2022 as a 2023 model, by which point we'll probably be looking at a refreshed version of the current Ford Ranger pickup, too. It seems likely that whatever hardcore off-road package is put together for the Bronco will make its way onto that truck, too.