Looks like the larvae of an **elephant hawk moth** ( ** _Deilephila elpenor_**).

* 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 variation](
_D. elpenor_ color variation. Source: A.R. Pittaway & 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