Caterpillar resembling a snake
Looks like the larvae of an elephant hawk moth (Deilephila elpenor).



 Green Variant. ©2005 Henk Wallays  (CC BY-NC 3.0) 


In the Sphingidae family (like the snake-mimic caterpillar in this post).


Description: typically brown-gray color with black dots along length of body. Young larvae are yellowish-white or green, but some mature larvae also can be green colored. Fully-grown caterpillars reach 7.62 cm in length.


Have a backward curving spine or "horn" on the final abdominal segment.


 

 D. elpenor color variation. Source: A.R. Pittaway &amp; I.J. Kitching 

Range: Most common in central Europe and is distributed throughout the palearctic region.

Habitat: variety: including rough grassland, heathland, sand dunes, hedgerows, woodland, open countryside, and even urban gardens.

Source: Wikipedia