Maybe it’s because it’s Sunday night and I’m missing “The Walking Dead.” Maybe it’s because “Zombieland” is on TV.

But zombies are on my mind tonight.

What is it about zombies that make them ideal fodder for spooky fiction? Maybe it’s because they’re so inexorable, shambling toward us — or sprinting, in some movies. Maybe it’s because they are — or were, at least — us.

Maybe it’s because they’re fun.

Zombies have lurked around the edges of pop culture for much of the past century, first popping up in Depression-era stories, usually set in Caribbean countries.

The 1932 movie “White Zombie,” starring Bela Lugosi, popularized the idea of the zombie as a glassy-eyed, stiff-gaited creature, usually controlled by a voodoo master. Zombies became staples of cheap monster movies for decades … until another cheap monster movie changed everything.

In 1968, George Romero and a handful of investors released “Night of the Living Dead” and set the tone for zombie flicks for years to come.

The black-and-white film, with its cheap gore and shockingly downbeat ending, wasn’t topped for another decade and then only by Romero himself.

“Dawn of the Dead” came out in 1978 and succeeded on so many levels. The film, in eye-popping color, featured explicit gore — the film was released unrated to avoid an “X” — and biting social commentary as survivors and zombies alike flocked to the shopping mall for a comforting reminder of the past.

The movie was such a hit that imitators and rip-offs followed, including 1979’s “Zombie,” a European shocker that was marketed in some countries as a sequel to “Dawn of the Dead.” “Zombie” featured the first shark vs. zombie underwater fight. First and, probably, only.

In 1985, “Return of the Living Dead” gave us a real change-up. While Romero continued to make (only sometimes effective) sequels to “Night” and “Dawn,” the co-holders of the rights to his 1968 movie made the first of a series of flaky, crazy, gory zombie pics. Famous for moments including reanimated medical specimens and zombies calling for “more paramedics,” “Return” was the most fun you could have with zombies. At least for a few years.

An often-overlooked zombie movie was “The Serpent and the Rainbow,” a Wes Craven movie starring Bill Pullman in a story loosely based on real-life researcher Wade Davis. The 1988 film is offbeat and effective and finds as many chills in the bloody politics of Haiti as in the walking dead.

Beginning with 2002’s “28 Days Later,” and remakes of “Night of the Living Dead” and “Dawn of the Dead,” zombies started getting nimble, fast and, in many ways, scarier. All of a sudden, zombies didn’t shamble slowly across a sunny graveyard. They ran like hell at us. It was freaky.

By the time “Zombieland” rolled around in 2009, the trends of fast zombies and gruesome and funny zombie deaths were fodder for a great movie. A small group of survivors travels across the country, looking for Twinkies and trust and finding Bill Murray — in one of modern cinema’s great cameos — and an abandoned amusement park. Well, not totally abandoned, of course.

With “The Walking Dead” comic book and TV series and Max Brooks’ great 2006 book “World War Z” — being made as a movie starring Brad Pitt — zombies are riding a crest of popularity right now. Zombie costumes were huge this Halloween. They were cheap to make and, after decades of watching zombies in movies and on TV, everybody knows how to pretend to be a zombie, right?

I love me some good vampire stories, particularly “Dracula” and “Buffy the Vampire Slayer.” But zombies are the monster of the moment, maybe improbably, and that popularity doesn’t show any signs of slowing down.

And neither do those damn zombies.