Naryciodes Caterpillars: these caterpillars have gummy-like bodies with features that mimic the appearance of a snail; they even have appendages that resemble eyestalks, but they’re actually located on the caterpillar’s rump
The scientific name of this species is Naryciodes posticalis. It belongs to the Limacodidae family of moths, which are commonly known as slug moths, thanks to the gelatinous, slug-like appearance of their larvae. That name seems a little ironic in this case, because Naryciodes posticalis actually mimics a snail.
Above:Naryciodes posticalis caterpillar
The caterpillar has a bulge in the center of its body, with colorful markings that form three concentric layers. These features mimic the appearance of a snail’s shell, which may help to deter predators. It also has a pair of short, stubby appendages that resemble eyestalks, but they’re located at the back of the caterpillar’s body.
Above: this photo shows the underside of the caterpillar’s body, with its mouth slightly visible on the right
This species is found only in Japan.
Despite my best efforts, I couldn’t find any other information about these strange little creatures, and I get the sense that the entire genus is poorly studied.