What “classic” actually means

A proper classic yellow rubber duck is vinyl (the old hard-rubber chew toys are antiques), about 8–10 cm, weighted so the beak points up, with a hole in the tail and a squeaker you will eventually regret at 6am. Unweighted ducks lie on their sides and look drowned. That is the whole review.
Highlight · Amazon UK search
Schylling-style classic
When people mean “the yellow one”, this is the search that usually surfaces a weighted floater rather than a pirate hat. Ignore costumes on the first page if you want the desk toy for rubber-duck debugging.
A bag of mini rubber ducks is for a treasure hunt, not a desk. Fine as a party pack; miserable as a single gift. Jumbo ducks are a joke that works once, in a garden, and then need a shed.
Collector vinyl
Lilalu (Germany) and BUD-style collectables are the other honest category: outfits, jobs, tiny medals. They are gifts for people who already have the yellow one. They are not better bath toys. Many collector ducks do not float upright — they are sculptures that happen to be duck-shaped.
Highlight · Amazon UK search
Lilalu collector ducks
Hundreds of designs — pirate, guard, craftsman, seasonal. Search the brand, then the theme. BPA-free and CE marks matter if it is going in a baby bath; many collector lines are for display.
BUD ducks (often sold as “Bud Ducks”) are the other named line that UK searches still return: constable, royal guard, rainbow. Same rule — search the name plus “rubber duck”, do not pin a SKU that vanishes next month.
The catalogue
Use the search that matches the job. Each cell is a category, not “this exact duck”.
Classic yellow
Weighted, ~8–10 cm, one squeaker. The 1992 story, the debugging desk, the actual bath.
Baby bath (safer materials)
Look for CE marking and “BPA free” in the results. Skip cheap painted minis for infants.
Mini pack
A dozen small ducks for a hunt or cake. Not a desk toy. Check they are too big to swallow.
Jumbo / giant
Garden joke, pool prop, once. Measure your shelf before you click.
Pirate / novelty
Lilalu and generic costume ducks. Fun; often poor floaters.
British guard / constable
BUD-style souvenir ducks. Search the job, not a film licence.
Desk / debugging
One quiet yellow bird. If it wears a hat, you have already lost the joke.
Collector brand: BUD
Named line, presentation boxes, sealed holes on some models. A collection, not a bath set.
What we will not catalogue
Licensed film characters go stale and pick fights with trademarks. Slogan ducks (“what the duck”) are the slippers of the toy aisle. Anything with a sharp painted beak for a baby is a no. If you came here from science or the map, the better present is still binoculars or a field guide. The yellow bird is allowed to be a joke. The wild one is not.