The Caterpillar-Mimicking Spider: this species of jumping spider mimics a lichen moth caterpillar, possibly as a way to deter predators
This species (Uroballus carlei) is sometimes referred to as a caterpillar jumping spider or caterpillar jumper, because it bears such a striking resemblance to a caterpillar. It was discovered in Hong Kong just a few years ago.
Researchers believe that these strange little spiders mimic the caterpillars of local lichen moths, which may help to deter predators. Lichen moth caterpillars ingest toxic substances that make them unpalatable to predators, and they're covered in urticating hairs that cause pain and irritation when touched, so predators tend to avoid them. They also have aposematic features that advertise those defense mechanisms, making them an excellent model for mimicry.
The spider's resemblance to a caterpillar may serve as a defense mechanism against larger vertebrates, such as birds, and as a predatory ploy against certain invertebrates, like small beetles, thus allowing the spider to avoid being eaten while also enabling it to stalk and capture its own prey more effectively.
This article described the discovery back in 2019:
A new spider has been discovered, hiding in plain sight in one of the most populated places on the planet. And there’s a good chance it went undiscovered for so long because it doesn’t really look like a spider at all, but more like a fuzzy baby caterpillar. Its cute, fuzzy appearance has led the newly discovered spider to be named Uroballus carlei, after Eric Carle – author of the wildly popular children’s book The Very Hungry Caterpillar.
Living alongside Uroballus carlei in the wooded areas of the Eastern District in Hong Kong are lichen moths. During the caterpillar stage, these moths are covered in bristly brown fur not dissimilar to Uroballus carlei. They live on a diet of lichen, and it’s this diet that gives them their name.
Journal of Entomology: A New Species of Uroballus from Hong Kong: a Jumping Spider that Appears to Mimic Lichen Moth Caterpillars (PDF)
University of Manchester: Newly Discovered Jumping Spider is Master of Disguise
University of Manchester: Newly Discovered Jumping Spider Named for Children's Author
BBC: Spider Named After The Very Hungry Caterpillar Author, Eric Carle