Brown Tail

Back to the moths: this is a brown tail, Euproctis chrysorrhoea. It is in the tussock moth family and there's a very similar species with a yellow tail. 
The caterpillar's hairs are incredibly irritant to skin, so much so that wind-blown hairs can cause problems to people some distance away! Remember that next time you find yourself scratching unexpectedly. (Although they are largely confined to the south of Great Britain.)