Monarch Caterpillar J-ing - Danaus plexippus

I found this caterpillar attached to the underside of a leaf (not milkweed) in the characteristic "J" shape, which indicates that it's getting ready to pupate. While J-ing, it no longer eats, but just hangs there and is particularly vulnerable to parasitoids and predation. You can see how the colors are starting to change as it prepares for the process.

Spotted in a rural garden, attached to a leaf. There were milkweed plants a few feet away.