Forty years ago this month, The Muppet Show debuted. Since then, whole generations have grown up with Kermit, Miss Piggy, Fozzie Bear, the Swedish Chef, and thousands more.

But while you probably know your Muppets, do you know your Muppet lingo? Check out the 12 terms below and find out.

antron fleece

While Henson's early creations were made from hard materials such as papier-mache, says How Stuff Works, he later chose softer materials that would allow for more facial expressions. One of those materials was antron fleece, that fuzzy-looking Muppet skin, also known as Muppet fleece.

Antron fleece seems to have been created by the DuPont chemical company. The Antron brand was sold in 2004 to Koch Industries, along with Lycra, Dacron, and others.

Børk! Børk! Børk!

Børk! Børk! Børk! is the last line of the Swedish Chef's signature song. The phrase, and everything this particular chaos Muppet says, is mock Swedish. (The Muppet wiki points out that the letter ø actually doesn't exist in Swedish and that it should be ö.)

Slate asked real Swedish people what they thought of the chef's gibberish. Some responded that it sounded more Norwegian than Swedish, although one Swedish linguist thought his accent could have easily been either.

full-bodied Muppet

Think Big Bird, Mr. Snuffleupagus, and the Gorgs. Full-bodied Muppets are Muppeteers in what are essentially Muppet suits.

In the case of eight-foot two-inch tall Big Bird, the operator wears shoes with five-inch heels and raises his right hand above his head to maneuver Big Bird's mouth. His left hand works Big Bird's left arm, while a wire attached to the left works Big Bird's right.

As for "Snuffy," it takes two people to work the costume, one for the front and voice, and one for the back.

hand-and-rod

In a hand-and-rod Muppet, the Muppeteer works the head of the Muppet with one hand and the arms of the Muppet by way of two rods with the other. Grover and Kermit are both examples of hand-and-rod Muppets.

How Stuff Works says most Muppets are left-handed "because the Muppeteer's right hand is busy operating the head."

Henson stitch

The Henson stitch was invented by Muppet designer and builder Don Sahlin and named, by Sahlin, for Jim Henson.

This blind stitch, paired with a "fuzzy pile of antron fleece," says How Stuff Works, "makes stitches virtually disappear," which is handy for television close-ups. For example, audiences at home never see the stitch running right down Kermit's nose.

Magic Triangle

The Magic Triangle was also invented by Don Sahlin, and refers to the shape created by the perfect placement of a Muppet's eyes and nose. Such placement gives the Muppet "focus and character."

Other magical and mysterious triangles include the Bermuda Triangle and the golden triangle in mathematics. A magical-in-a-different way triangle is the Golden Triangle of Southeast Asia, three countries that make up one of Asia's main opium-growing regions.

Muppet

Henson coined the word Muppet in the 1950s when these "humorously grotesque glove puppets," as described by the Oxford English Dictionary (OED), were introduced in TV commercials for Wilkins Coffee.

While in a 1978 interview with Time, Henson claimed muppet didn't mean anything and "simply sounded good to him," in a 1959 article he had explained that the word was a blend of puppet and marionette. It might also be a play on moppet, a young girl or a puppet made of cloth.

platforming up

Henson invented this technique of raising sets 8 to 10 feet so that Muppeteers can stand at full height rather than crouched down (a position which Henson, at six foot plus, must have found uncomfortable). Some more petite Muppeteers apparently wear platform shoes to reach the raised stage.

However, when performing with children, as was often the case on Sesame Street, Henson would make an exception. Instead of placing the child at "such a perilous height," he would kneel on the floor beside her and raise the Muppet to meet her eye-to-eye.

puppet switching

Puppet switching is switching between hand and full-body Muppets. This technique might be required for scenes involving long-shots of Muppets doing things like roller-skating, as Miss Piggy does when she chases down a mugger in The Muppets Take Manhattan.

right-handing

You may notice that Rowlf the Dog has two human-like hands (as opposed to hands and arms controlled by rods) and a moving head. How does one Muppeteer work such a Muppet by himself? He doesn't.

While one operator works Rowlf's head and left hand, a second Muppeteer is in charge of the right. This is known as right-handing. Right-handing is used in what are called live-hand Muppets like Rowlf the Dog, as well as Fozzie Bear, the Swedish Chef, Dr. Bunsen Honeydew, Ernie, Cookie Monster, and Count von Count.

The first job of Frank Oz, voice of Miss Piggy, Fozzie Bear, Cookie Monster, Grover, Bert, and, by the way, Yoda, was right-handing Rowlf the Dog with Jim Henson.

whatnots

In Muppet lingo, whatnots are Muppets with blank heads, on which various eyes, noses, hair, and clothes can be fixed to create extras or miscellaneous characters. On Sesame Street, such Muppets are known as Anything Muppets.

The word whatnot first appeared in the the mid-16th century, says the OED, meaning "anything and everything," or "all sorts of things." In 1808, the word came to refer to a kind of furniture with shelves for keeping "various objects," such as ornaments, knickknacks, books, papers, etc.

In the early 1960s, whatnot became a euphemism for something the speaker didn't want to name: "By the time I was fourteen I'd been a court witness in an indecent exposure case after an Indian doctor had been caught flashing his whatnot at me."

wocka wocka!

Wocka wocka! is Fozzie Bear's catch phrase, usually said right after a (bad) joke.

It seems wocka-wocka has come to refer to any corny joke that falls flat, as used in this 2005 NY Times article: "There [were] countless wocka-wocka one-liners from 20-something stand-up comedians (‘Over here in New Jersey, my wife is giving me a big cold front')."

Waka Flocka Flame is an American rapper who often wears a large bejeweled Fozzie pendant when he performs, as one does.