It is feeding on the flowers of the pine cone ginger lily. The knobby, “pinecone” head of this plant which sprouts flowers from the scallops in sequence, is filled with a sweet smelling, slightly viscous fluid that is reportedly a native American replacement for soap.
The caterpillar is ravenous as most are. This one doubled its size from 1/4" to 1/2 inch in two days.
I will identify and post the name later. I suspect it is a moth cat.