Oak Eggar Caterpillar (Lasiocampa quercus)
This caterpillar is an oak eggar, closely related to the oak processionary caterpillar (Thaumetopoea processionea). It may look somewhat intimidating however unlike the oak processionary caterpillar, the hairs of this species of moth do not cause skin irritation.
Nevertheless I kept my distance to this one just in case and used a telephoto macro lens to get the shot.