Unknown ID

Unknown ID

Observation - Unknown ID. Description: Found on the Pembrokeshire Coast Path near Trefin. Green metallic sheen as evident in photo. 6 short legs at front end. I assume it's the larval stage of something but what?

Found on the Pembrokeshire Coast Path near Trefin. Green metallic sheen as evident in photo. 6 short legs at front end. I assume it's the larval stage of something but what?