What on earth is this going to turn into? Presume it's going to be a Moth?

While at my never ending project of picking stone off an area I will (NB positive attitude)eventually turn back into field I found this below. I have never seen anything like it before but maybe it is a common caterpiller. It's about 2 to 3 inches long and really quite imposing.
I have it in a pot atm and will wait to hear if it is friend or foe before it gets it's fate decided. Hope someone can identify it for me. Thanks

 

Elephant Hawk Moth

 

Blimey, never knew they went as far North as the ice sheet

They only eat weeds and fuchias @silu

 

Oh thanks @Jiffy. I have just googled it and yes you are spot on and it likes Rosebay Willowherb. Guess what is growing with great gusto on the stony field area...you guessed.
Up to your usual cheeky standard @Zigs. The caterpillar is back up in the field carefully placed on the best bit of Willowherb I could find. I do have Fuchias growing here but hopefully it will stick to the vast array of weeds to choose from in the field.
Yes it really is amazing zigs what is able to live up here and copes with the permanent permafrost! Just off to wax my skies as it looks like it might snow and oh yes by the way my outdoor Sweetcorn are just about ripe enough to eat.

 

Are you thinking of the Mammoth Hawk Moth