It looks as though it may be a vapourer moth. I just looked it up on a website. If it is not doing much damage to a crop I'm sure it is fine to leave. Most insects are fine unless there is an infestation of them. They all have their place in the garden.

Just checked what it eats - trees and shrubs, so your flowers and crops are safe. Isn't it nice - I really like this one!

I agree, Tina. It was probably found on the plant that it uses to pupate and turn into a crysallis. Where did you find it? If you look on the net for vapourer moth caterpillar, it'll tell you all about it, but please don't kill it. It won't do any damage. It's only cabbage white caterpillars and aphids that we need to get rid of as they do such a lot of damage.
Annie (Cumbria)

What a hairy little monster. If it's not damaging things leave it be. It may turn from ugly caterpillar into a beautiful moth/butterfly.

Yes, please leave it in peace on the plant where you found it---it will chomp a few leaves but I doubt it will harm the plant. It would be interesting to see the moth or butterfly! I shall look up vapour moth now!

the other thing is that as you put friend in a way its not . the gordy colours and long hairs mean its probably either poisenous or has a nasty iritant to stop things wanting to munch it . its very pretty but best left at arms length lol .

Google for pictures of Brown Tail Moth larvae - just make sure its not that. Your photo is rather dark, and I think I see red dots along its body, but the Brown Tail has those and white dots as well I think. You don't want Brown tail moth larvae anywhere nearby...