While it's rare to shoot a wild hog heavier than 250-300 pounds, bigger hogs do occasionally turn up. And these encounters with massive feral hogs seem to be getting more and more common in the United States as their numbers continue to grow. For instance, several hogs with confirmed weights of more than 400 pounds have made news headlines during the last few months.

When Chris Griffin killed the massive boar now known as "Hogzilla" in Georgia back in 2004, many people didn't believe that he'd actually killed a feral hog that big and accused him of making the whole thing up. In fact, National Geographic stepped in to do an investigation. They determined that Hogzilla was indeed real and probably weighed around 800 pounds.

An Alabama man named Wade Seago shot an 820-pound hog in his front yard with a .38 Special revolver to keep it from injuring his dog.

While still gigantic, the hog was not quite as large as originally claimed. As it turns out, the enormous wild boar had some Hampshire breed DNA and probably found some sort of supplemental food source — like high-protein fish food present on the fish farm close to where he was shot — that helped him get so big.

Fast forward to 2017 and people seem to be encountering these "monster" hogs more and more frequently. For instance, in October a man named Joe Clowers killed a 416-pound feral hog near his home in East Texas near Union Grove. Apparently, that hog had been causing trouble in the area for years, and Clowers always carried a rifle when he was out on his land just in case he encountered it.

Back in July, an Alabama man named Wade Seago shot an enormous hog in his front yard with a .38 Special revolver to keep it from injuring his dog. When he took it to an industrial scale the next day, the hog weighed an astounding 820 pounds.

The hog had no ear tags or markings of any kind, but it had some physical characteristics common to farm-raised hogs. Additionally, a nearby hog farmer thinks (but cannot confirm) that the hog Seago shot may have escaped from her pen.

Any way you slice it, though, that's a big darn hog that was running around the neighborhood.

In January, a 17-year-old in Virginia named Jacob Breeden looked out the window and saw a mammoth hog tearing up the yard. He grabbed a rifle and shot the hog. That boar measured 6 feet, 10 inches from nose to tail and weighed in at 545 pounds on a scale at a neighboring farm.

A 17-year-old in Virginia named Jacob Breeden looked out the window and saw a mammoth hog tearing up the yard. He grabbed a rifle and shot the 545-pound hog.

Those are just a couple of the encounters people had with massive hogs in 2017 that made headlines. There were undoubtedly more not covered here, and I doubt National Geographic will do a television show about any of them.

So, what's causing this apparent uptick in incidents involving gigantic hogs?

For one thing, feral hog populations are undeniably getting bigger, and hogs are expanding their range into new areas. Hogs over 400 pounds likely still make up a tiny percentage of the overall hog population, but the fact that the population as a whole is growing means that there are more hogs that size than there used to be.

At the same time, as hogs continue to expand their range, encounters with humans are becoming more and more common. This gives hogs more access — sometimes intentionally, sometimes not — to supplemental sources of food like agricultural crops, pet food, garbage and livestock feed, which can help them grow to humongous size.

Some people speculate that this is what happened with Hogzilla, and it could very well be true with some of the other big hogs that have made news headlines. More contact with humans also translates into more opportunities for domestic hogs to escape farms and integrate with feral populations, which can also help explain why really big hogs seem to be occurring more frequently.

All that being said, shooting a wild hog that actually weighs in excess of 400 pounds remains an unusual occurrence. So, even if they are getting more common than they used to be, shooting a "monster" hog is still a newsworthy event.