No one looks his best dead and stuffed, and the gorilla Gargantua II is no exception.

In a glass case just inside the Seventh Regiment Armory at Park Avenue and 66th Street, Gargantua II is the prime exhibit in a collection of circus items being auctioned by Guernsey's today and tomorrow. The one-time Ringling Bros. and Barnum & Bailey Circus star appears mournful and a little embarrassed standing there. Maybe it's the glass eyes. They have this withdrawn look . . .

Gargantua II is not to be confused with his famous predecessor, Gargantua I, once advertised as "The World's Most Terrifying Living Creature." In one of the many antique posters Guernsey's is offering, Gargantua I is seen fleeing spear-wielding African tribesmen while clutching in one paw a native lass clad in a leopard-skin outfit. It is obviously the life for a Most Terrifying Living Creature; no glass case for him.

"This is unique," says Arlan Ettinger, president of Guernsey's, fondly regarding Gargantua II. "How do you put a price on something like this?" Someone, though, has found a way, because in the auction catalogue Gargantua II's value is put between $10,000 and $15,000.

He's not the most expensive item, though. Some of the carrousel animals are valued at as much, and a restored 1908 Barnum & Bailey band organ, all gold, red and cream scrollwork and shining brass pipes, is estimated to be worth $40,000 to $50,000.

But the jewel of the auction will go for at least 10 times that much. This is a complete working carrousel of 48 horses from the shop of Marcus Charles Illions. In a field that included such carvers as Gustav Dentzel (whose shop did the Glen Echo carrousel), Daniel Muller and John Zalar, it's hard to say that any one man's studio produced the "best" horses. But Illions' flower-bedecked steeds, with their delicate heads and flying manes, were the most magical.

Besides Gargantua II, the Illions carrousel and assorted carrousel animals, Guernsey's is auctioning circus posters, circus banners, handcarved circus miniatures and dioramas, arcade games, slot machines and part of circus historian Charles "Chappie" Fox's collection of periodicals, magazines, books, photographs and letters. This wealth of memorabilia -- "The largest auction in history of each commodity," claims Ettinger -- is available because James Managhan, the new owner of the Circus World theme park in Orlando, Fla., has decided to modernize. More rides, no historical exhibits.

"Circus World isn't cutting back," Barbara Mintz, the vice president of Guernsey's, explains, "they're expanding." "We're not cutting back," says David Woods, a Circus World representative, "we're expanding." There seems to be a nervous feeling in the air here that Circus World is going to come out a villain, abandoning cultural artifacts for the sake of profit. Trading in the hand-carved carrousel for the Santa Maria Shuttle Boat.

In fact, most of the articles up for auction had been sitting in a warehouse, uncared for. Some horses have missing legs. (The posters and banners, largely owing to the care of Chappie Fox, look almost new.) The carrousel, though, was a working ride -- the last operating Illions of its type in the world. An exquisite lifesize toy. A fairy-tale antique. "I've been standing there," says Woods, "when a kid would kick a leg off."

"There's always great controversy when a carrousel comes up for sale," says Ettinger. Collectors want it broken up and sold piece by piece. Preservationists want it kept intact. Guernsey's and Circus World are having it both ways. The Illions Carrousel is being sold complete (though two of the horses are temporarily on display at the Armory as examples of the quality of the whole), but an assortment of animals collected for a gigantic merry-go-round that was never built are being offered individually.

These line the armory hall as if it were a stable walk, their wooden heads thrust forward in attitudes of spirited excitement. Almost all are horses, though a tusked pig and a rooster turn up, and at one point a gold and green dragon gleams startlingly in the dim light.

The horses are by and large the work of the shops of Charles Looff, Charles Carmel and Allan Herschell. Sometimes even experts can't tell a Looff from a Carmel. The Looffs often have longer, narrower heads, but they share with the Carmels prominent facial veins and roccoco manes. Both types look high-strung. The Herschells are more simply carved and a bit homely, with Roman noses and protruding teeth. In comparison, the Illions horses, with their flower-woven manes and elaborate trappings, are demure and decorous.

But the animals that draw the most interest are a pair of giraffes, the taller one 6-foot-8. Carved by Dentzel and still sporting their original, 75-year-old paint, they stand side by side looking down their long noses at their admirers. They have prehensile-looking upper lips and delicate, spindly legs. The vaguely Moorish ceiling of the Armory forms an appropriate canopy.

Banners hang from this ceiling, huge hand-painted signs on canvas for the exhibits themselves. Some are of spectacle: "The Evolution of Horsemanship," for example, featuring a variety of running, leaping mounts; or a trainer with a whip standing among "The World's First And Only Group of Performing Black Leopards." But most are of freaks.

Cleo the hermaphroditic goat, for example. Cleo is a startled-looking little gray and white beast. His/her picture offers no evidence of his/her physical peculiarity, but the legend promises "Male And Female."

More peculiar is "Leo," who "Baffles Science." Leo is a diapered infant with very well-developed pectorals. He sits chucking what looks like a baby wallaby under the chin. Beside him lies what is either a doll or a dead monkey. He has a second face growing on the right side of his head. Presumably it is this, and not his ability to calm skittish wallabies, that baffles science. But it doesn't pay to be too certain about these things.

Then there is the bikinied Fat Lady, who, under the caption "Oh My? But She Is Fat," drags a tiny, reluctant male to frolic in the surf.

Even this giantess is eclipsed by the Elephant Girl, a brown-haired, snub-nosed woman with the body of an elephant. She stands beneath a palm tree gazing out at us. Behind her, two real elephants, their heads close to each other, eye her suspiciously. Her dark eyes are a little crossed. Her face, with its specifically rendered features, is disconcertingly personal -- as if it were a portrait.

Monsters. Freaks. Enchanted wooden animals.

The purveyors to the public's taste for the bizarre and the exotic, the brothers Ringling, got their start on April 19, 1884, in Baraboo, Wis. The occasion is memorialized in one of the nine dioramas carved by Gene Leroy that trace the history of the circus from 1870 to 1970.

The dioramas are charming, like primitive Red Grooms pieces. More sophisticated are the circus miniatures of Robert Clarke, carved on a 1-inch scale by Clarke, Charley Dech and John Lower. Clarke created a full miniature menagerie, complete with yaks and llamas, plus wagons, cages, horses, sideshow banners and scenes of circus people at work and relaxing. There's something a little mad about Clarke's achievement. It's an obsessive's triumph -- the collection and miniaturization of an entire way of life.

The auction estimate for Clarke's Big Top scale model, with its 14 circus wagons, performing animals, jugglers, clowns and dozens of other characters, is $30,000 to $40,000. The set of complete dioramas is expected to go for $100,000 to $120,000. The Gargantua poster is valued at $500 to $600.

In the end, to be sure, the auction isn't about cultural history, or how audiences have changed, or the passing of a way of life. It's about money. It's about collecting. It's about "life style." Examining a Looff horse, a well-dressed woman explained to a friend why she was in the market again: "My husband and I split up, and we split the animals."