They're sometimes called nodding dolls, or, more formally, pagods, or, less formally, bobbin' heads or bobbleheads, but the one thing they have in common is a mechanism to make their heads move up and down.

The first examples originated in China, where they were used in religious temple rites to represent deities. The earliest examples were made of brass and were in the form of bells: when the bell was rung, the head of the figure would nod. The idea was adapted by the Meissen porcelain factory in the early 18th century and then picked up by French makers who produced bisque as well as china nodders. They reached a peak in 19th-century Germany, where they were made of a variety of materials, principally bisque, porcelain and wood. Originally, heads and hands were attached to wires, so that the slightest movement would cause the part to move up and down.

During the Victorian era, toy manufacturers began to market a variety of novelty items using the bobbing technique. Construction gradually became more complex, so that not only heads but individuated mouths, ears and tails moved through various means — some rocking back and forth on small plastic prongs, others jiggling from side to side via more ingenious attachments. Starting in the 1920s, the German firms of Hertwig & Co. and H & J Foulke made a series of elastic-strung bisque nodders with molded clothes that included, along with comic characters, dressed teddy bears and other animals, Santa Clauses, a Dutch girl and a "Hitler Youth" boy and girl pair.

There was a strong resurgence of interest in the form in the 1950s and 1960s, when there was a burst of activity in the production of plastic nodders. Among them, for example, are several sets of nodding Beatles figures that are, of course, coveted by Beatlemaniacs. Two of the sets consist of 4-inch plastic dolls, one with movable instruments, the other with fixed instruments. Some other crossover collecting areas include Black memorabilia, Christmas collectibles and Disney items. Countless Disney character nodders have been made over the years, including many Mickeys and Minnies, a 6-inch Donald Duck toy with wind-up rubber-band action, made in Japan in 1934, and a group of composition and papier-mache nodding-head Donalds produced in Germany in the '30s.

Novelty sports-figure nodders have been popular modern collectibles dating back to a New York Knicks player marketed in the 1920s. They became something of a craze in the '60s, when team members had to be identified by their uniforms, as the heads were often remarkably similar. A Mickey Mantle example made in 1962 was valued a couple of years ago at $700.

What are some other collectible nodder categories? Advertising icons (Charlie Tuna, Col. Sanders, Bob's Big Boy), cartoon characters (Betty Boop, Felix the Cat, Popeye, an extremely scarce plaster-composition Maggie & Jiggs pair currently valued at $695), TV characters (a very rare Dobie Gillis was recently offered for $395) and a 1960s Japanese sub-genre known as "The Uglies." Some people also collect nodders only of certain materials — bisque, ceramic, celluloid, etc.

As has been seen, there is an extraordinarily wide range of prices for bobbing-head figures. One elaborate papier-mache father rabbit carrying three small bunnies was auctioned for an astounding $30,800 and now resides at the Old Salem Toy Museum in Winston-Salem, N.C. An early Meissen Buddha might be priced at $10,000-plus, and even vintage celluloid nodders of comic characters like Donald Duck, Pluto and Felix the Cat can fetch in the mid-to-high three figures. On the other hand, on eBay today, there's an Alex Rodriguez Texas Rangers nodder, in its box, that can be yours for $5.99.

Linda Rosenkrantz has edited Auction magazine and authored 18 books, most recently "Beyond Ava & Aidan: The Enlightened Guide to Naming your Baby" (St. Martin's Press). Visit her baby names website at http://nameberry.com. She cannot answer letters personally. To find out more about Linda Rosenkrantz and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.