We have quite a few pots of Madonna Lilies (aka Peace Lilies, Spathiphyllum spp.) around the house; they do well until they are eaten, which happens with some regularity. Looking down into a pot yesterday, I saw a couple of the usual suspects lying on the dirt as though they were sleeping off their gluttony.
They are Hawkmoth (Sphingidae) caterpillars, Eupanacra splendens. The species appears to have no common name, which is hardly surprising when we remember that many of the species are very similar (although the whole family is quite distinctive) and that the adults fly only at night.
Madonna Lilies are one of their two favourite foods, at least in our garden. The other is Pentas, which is also a food plant for the adults.
The caterpillars eventually pupate underground. There’s a picture of the pupal case on this page along with pictures of caterpillars and adult moths.