Green caterpillar

Green caterpillar

Observation - Green caterpillar. Description: Green caterpillar found by compost bin (not on orginal leaf).Have found these one or twice in garden.Any ideas? Raised itself up in defence as seen in picture 8

Green caterpillar found by compost bin (not on orginal leaf).Have found these one or twice in garden.Any ideas? Raised itself up in defence as seen in picture 8