That's.... not a caterpillar. That's the larvae/maggot of the common cockchafer, as far as I can tell. Otherwise known as Maybug.

The black egg is century egg, a duck or chicken egg preserved in an alkaline solution (usually quicklime, ash, salt and rice hulls). It's not horrible in the way, say, surströmming is, but it an unusual taste and texture that makes most people balk at the idea. Honestly, I'd pick it over even the onion.