You might love your tiny ceramic cat wearing a sombrero, but it’s just a knickknack, a small collectible ornament. A knickknack isn’t valuable — except sentimentally.
Little statues, candles in quirky shapes, or prizes found inside cereal boxes, are all knickknacks. Anything that decorates or clutters the shelves of someone's home, especially if it's basically worthless, is a knickknack. The word knickknack was originally a 16th century version of "dirty trick," from knack, and its now-obsolete meaning "deception or trick." Don’t freak out if it’s spelled knick-knack because that’s ok too.