I hope you're still letting him feed on your fuschia leaves? He still needs them before he turns into a chrysalis.

I love these.Its amazing it ate such a lot of your fuchsia even though he's a biggie!

I think that it has buried itself in the soil ready to pupate. Will keep taking photos when I find the pupa and also when it changes into a moth.

Yes it looks like an elephant hawkmoth. The big spots like eyes on its body are to deter predators. It will turn into a brown and orangey moth which I found a bit disappointing after the magnificence of the caterpillar! We need to preserve them though, and fuchsias are the favourite foodplant.