Big caterpillar about 12 cm length. It has smooth body surface.
Lowland green area - savanna - found on small climbing herbs.
I just got lucky find this one at my walk to campus. I brought a binocular for birdwatching, but see this one make me put my bino on the ground, also my bag. Try to capture this one using my pocket camera, got luck. Thanks @bayucca for the ID!