caterpillar fungus (Ophiocordyceps sinensis) (The fungus grows within the body of a caterpillar, culminating in the emergence of a stalked fruiting body from the caterpillar's head, and is a much-prized and expensive ingredient used as a tonic in traditional Chinese medicine.)
trad. 冬蟲夏草
Also written 冬蟲夏草【dōng chóng xià cǎo】