Legion's demon-lady who tries to eat the girl from Friday Night Lights has been the thrust of most of that angels-with-guns flick's previews. Because crazy old ladies put butts in seats, guaranteed! Why, they're one of five cheap trailer ploys.

There are a lot of these preview tricks — awesome explosions, people about to yell swears but then getting cut off, Megan Fox — that marketing folks use to secure an audience based off of two minutes of smashed together footage. But five in particular seem to reign supreme. They are as follows.

Wacky Elderly Women

Yes, we are dying to see Legion, and yes it is mostly because that pink-sweatered old biddy just up and jumps on the wall and crawls around like an ancient spider. It's thrilling and a little scary and mostly hilarious! And it will absolutely sell tickets. There's just something about old ladies busting out with the evil or the funny (or both) that even a brief glimpse of it will make us all mad and frothing to see that fucking movie. Just look at the happy returns for The Wedding Singer and The Proposal, both of which prominently featured hip grannies in their trailers. While we're mostly wary of the elderly in real life, we just love seeing them behave oddly from the safety of a flickering screen.

Cats & Dogs in Hilarious Peril, Pigs Being Pigs

While we all love cats and dogs — they are cuddly and oftentimes our only companions in this rotten, lonely old world — we also love to see them getting fake hurt. You know, jumping out of windows or being electrocuted. Funny stuff like that. We also really like pigs, especially when they are walking on walls, like in The Simpsons Movie. That whole "Spider Pig" gag single-handedly sold that movie to a lot of folks. Just as, we're told by an industry insider, the tuxedo-clad, cake-eating pig in the trailer for the regrettable Yours, Mine, & Ours remake became a huge part of the promo blitz once it tested well. America loves animals! Especially when they're filthy and/or in serious danger.

One Night in Bangkok

Oh man. This had fallen slightly out of favor in recent years, but now it appears to be making a resurgence, appearing in the trailer for Old Dogs and Grown Ups. Its golden age was about ten years ago (mostly in the post-Home Alone violent kids comedies), when every damn movie had some poor schlub getting a whack right in the briar patch. Excruciating pain is always funny, but it is especially funny when it involves a man's disgusto and made-for-hitting private parts. Movie studios know this — that we flock to injured balls like moths to dangling, flickering flames — so they cart it out over and over again. And it never gets old, until you do. Like horror movies in which a bunch of possibility-laden youngsters get brutally hacked to chum by a vengeful maniac have, with age, started to make us feel sad rather than scared, nuts-crackin' comedy eventually goes from entertaining to just plain old ugly and painful. Mostly you look these days — at the screaming teens, at the unsuspecting mook unaware of that speeding baseball — and you just think, "Oh, how awful." (Though, we will never not like Man Getting Hit by Football or the George C. Scott remake.) But whatever! We're not the intended audience, so trailer editors will just keep thwacking away.

That Baby Can Talk! Kill It!

Who doesn't love a movie with a smart alec kid or a magical talking baby that swears or something? This is in the same vein as the wacky old people, just on the other end of life's troublingly short spectrum. The apotheosis of this hook is obviously Baby Geniuses, a movie made entirely of hook and nothing else (except Kathleen Turner). But you see snippets of this particular device elsewhere, from Abigail Breslin's world weariness in the No Reservations trailer to the classic "pitcher's got a big butt" in summertime smash movie preview Rookie of the Year (also: "Funky butt-lovin'"!). Children shaming and condescending to adults is never not terrific, the thinking seems to go. And putting one of those tot bon mots into the preview is just common sense. Like ball jokes, you mostly grow out of getting reeled in by this shtick. Because now you are the lame adults. And the sassy kids are that sarcastic infant on Modern Family. You know, the one with the glasses. Smarmy little brat...

Poop.

There's not much to say about this trope. Poop in a movie preview means people will buy tickets. See: Alvin and the Chipmunks, in which a CGI chipmunk actually eats poop in the trailer; Meet the Parents, in which celebrated actors Robert DeNiro and Blythe Danner get showered in feces by Jerry Stiller's son; and Two Weeks Notice, in which Sandra Bullock almost soils herself. Poop sells. So, put it up front, before another movie about crap.

Note: Both Sandra Bullock and Dennis Quaid are each in two films mentioned here. What does that say about them? Anything?