Large caterpillar

Large caterpillar

Observation - Large caterpillar - UK and Ireland. Description: Any ideas what this large furry caterpillar is. I saw several on the sand on the land side of the dunes and one on a Sea Buckthorn.

Any ideas what this large furry caterpillar is. I saw several on the sand on the land side of the dunes and one on a Sea Buckthorn.