(Mental Floss) -- Your mission, if you choose to accept it, is to seek out covert items at fast food chains around the country.

Not all food items are always listed on restaurant menus.

Be warned, this mission includes very real dangers such as hardening arteries and skyrocketing cholesterol. We've compiled a list to get you started.

1. If you're at Starbucks and in need of just a little caffeine, don't worry -- there's a tiny option for you. It's the Short size, and they don't advertise it. It's like a little baby cup of coffee. It also comes in handy when you're scrounging for change and don't have enough for a tall (not that that has ever happened to me).

2. It's a good thing we don't have Jamba Juice here in Iowa, because I would be all over candy-based smoothies. Because it's considered a health-food chain, Jamba Juice doesn't officially list these on their in-store menus, but the Web site Mighty Foods assures us that the secret flavors exist.

The ones they confirmed with the company's headquarters include Strawberry Shortcake, White Gummy Bear, PB&J, Various flavors of Starbursts, Fruity Pebbles, Push-Up Pops, and Skittles. Other tantalizing flavors that are rumored to exist: Chocolate Gummi Bear, Apple Pie, Sourpatch Kid, Tootsie Roll, and Now and Later.

3. This one might be my favorite. At Fatburger, you can order a Hypocrite -- a veggie burger topped with crispy strips of bacon.

4. Chipotle has a whole secret menu that is limited only by your imagination -- they have a store policy that says that if they have the item available, they will make it for you. Things that have been tested include nachos, quesadillas, taco salads and single tacos. Some stores are testing out quesadillas as a regular menu item, however, so maybe someday soon you won't need a super-secret handshake to order one. Mental Floss: 7 food promotions gone horribly wrong

5. If you're at Wendy's and you're really hungry -- like, three-patties-just-won't-cut-it hungry -- go ahead and order the Grand Slam, which is four patties stacked on a bun. This option is only available at select Wendy's, and it's also known as the Meat Cube.

6. Several places, including McDonald's and In-N-Out, will serve you the Neapolitan milkshake. It's just what it sounds like -- chocolate, vanilla and strawberry shakes layered in a cup.

7. In-N-Out Burger's "secret menu" isn't so secret these days -- in fact, they've posted it on their Web site. But in case you're not in the habit of surfing fast food Web sites, here's the skinny on their rather un-skinny items: ordering something "Animal Style" at In-N-Out means you're going to get it with lettuce, tomato, a mustard-cooked beef patty, pickles, extra spread (it's sort of Thousand-Islandy) and grilled onions. You can even get your fries Animal Style. Mental Floss: Why is it called "Thousand Island" dressing?

"Protein Style" is a burger wrapped in a lettuce leaf instead of a bun. A Grilled Cheese is two slices of American cheese, lettuce, tomato and spread on a bun (grilled onions if you so choose).

And you can get just about any combo of meat and cheese that you want if you order it like you're ordering lumber: 3×3 gets you three beef patties and three slices of cheese, 4×4 gets you four of each, and so on. According to photos posted at SuperSizedMeals.com, one gluttonous patron requested and received a 100x100 at a Las Vegas store a few years ago. One item not listed on the Web site secret menu: the Flying Dutchman, which is two slices of cheese sandwiched between two patties, hold the bun.

8. Feeling a little health-conscious at Popeye's? If you are, you really should have gone somewhere else. But there's a little hope for you -- ordering "naked chicken" will get you breading-free poultry. The word is that this is on the menu at some Popeye's, but not all of them, although it is an option at all of them.

9. Like Chipotle, Taco Bell will make you just about anything within reason as long as they have the ingredients for it. Since most of the food at Taco Bell is made out of the same basic items, that means you can probably ask for most discontinued items and get them. One "secret," though, is that they have a not-advertised green chili sauce at most locations, and apparently it's excellent.

10. Some Subways will still make you the popular pizza sub from the 1990s. Once the chain decided to make their focus healthy eating, the pizza sub disappeared from the menu in most places (the word is that Canadian and Mexican Subways still offer them on a regular basis). But if you ask, lots of places will still make it for you. Be warned, though -- Jared would not approve of the nine slices of pepperoni and copious amounts of cheese slathered in marinara sauce. Mental Floss: Brief history of dubious dieting

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