(FORTUNE Magazine) – AS BEFITS a mature frog, Kermit has left the lily pond for corporate America. Not that the arch Muppet has forgotten his calling. In mini-films and videos designed for business meetings, he and a cast of new characters--including Leo, the young go-getter Vice President of Dubious Affairs, and Grump, the crabby company man--are leaving thousands of otherwise serious professionals laughing. Breaking businessmen up is greening Muppetland's bottom line, and a batch of new films is on the way to cash in on the craze. The two- to four-minute vignettes, which can be used to open, close, or interrupt a long meeting, poke fun at the business world. With names like ''Sell, Sell, Sell'' and ''Let's Have the Dam Break,'' the films parody such corporate vulnerabilities as boring technotalk, overly zealous salesmen, and efficiency nuts. In a gentle mockery of the acronym mania, for instance, Leo lays out ''the plan for future planning,'' called PLAN (packaged line analysis nexus), which is both BIG (business improvement guaranteed) and BAD (bold and decisive). Gray-flannel fans from Citibank to the CIA say the films do more than amuse. ''They're such a complete switch that people listen better to the rest of the meeting,'' says Gordon Laird, marketing services manager at Exxon's chemical division in Houston. The corporate Muppets also tie a group together because they represent attitudes common to just about every businessman, says Jim Henson, 48, lord of the Muppet empire, Henson Associates (or HA!, as he calls it). Today HA! counts to its credit the internationally syndicated Muppet Show and HBO's Fraggle Rock along with numerous gold records, three feature films, and products galore. Big business sought out Henson in the late 1960s. David Lazer, then an IBM executive, was looking for a way to liven up in-house films for sales and training meetings. He happened to see a film of Henson's Muppets and asked him to come up with appropriate material for IBM. ''Jim made mincemeat out of the products, the company, and the people--in a very loving way,'' recalls Lazer, now an executive producer at HA!. The library has more than two dozen films, and sales, which grew mostly by word of mouth, have picked up lately. Some 2,000 companies came calling in 1984, most to buy films or tapes for $300 to $500 for each group of three to four vignettes, and the rest to rent them for $150 a group. HA!, which is very privately held--mainly by Henson and family--won't say how much the films make, but the business is evidently profitable enough to keep the film rolling. This year's entries: safety in the workplace and benefit packages, grown-up subjects to say the least. But the Muppets have a way of bringing things down to size.