Slug on wood

Slug on wood

Observation - Slug on wood - UK and Ireland. Description: About 70mm long &20mm across seemed to be about to eat a dead leaf. Apparently this variety is not a garden pest through eating prized plants, I first found it on the ground behind the wood on which it is placed in the picture amid lots of damp decaying l

About 70mm long &20mm across seemed to be about to eat a dead leaf. Apparently this variety is not a garden pest through eating prized plants, I first found it on the ground behind the wood on which it is placed in the picture amid lots of damp decaying leaves