The decorative snap-on charms that fit in the holes of Crocs are called Jibbitz.
Jibbitz are small charms mounted on posts that press through the ventilation holes in compatible Crocs shoes. They come in designs including letters, food, animals, sports symbols, characters, logos, and other pop-culture shapes, allowing wearers to personalize otherwise identical clogs.
The product began as a separate accessory business founded by Sheri Schmelzer. Designing a charm that would fit securely required several iterations; the finished charms were intended to snap into Crocs holes without using a strap or adhesive. That construction is why Jibbitz can usually be moved from one pair to another.
A common mix-up is using “Croc charms” or “shoe charms” as though they were the official product name. Those descriptions are understandable, and generic manufacturers also sell compatible charms, but Jibbitz is the canonical brand name associated with Crocs. Crocs acquired Jibbitz in 2006, helping turn the accessories into a major part of the brand’s customization culture.