This is a very rare glimpse into the Elephant Hawk Moth (deilephila elpenor) caterpillar mimicking a snake. When startled, the caterpillar draws its trunk into its foremost body segment. This posture resembles a snake with a large head and four large eye-like patches.
Once it reaches adulthood, the caterpillar morphs into a colourful moth, and then most likely eaten by a bat.