Caterpillar on nettle

 Caterpillar on nettle

Observation - Caterpillar on nettle - UK and Ireland. Description: Green caterpillar now about 35mm long which has been feeding voraciously on nettle leaves for the past 10 days - in captivity (watching it indoors in a ventilated container). Would love to know what it may turn into. Thanks

Green caterpillar now about 35mm long which has been feeding voraciously on nettle leaves for the past 10 days - in captivity (watching it indoors in a ventilated container). Would love to know what it may turn into. Thanks