What's eating my dahlias?

   My lovely dahlias and English Marigolds have been munched until they look like confetti.  I was deadheading the dahlias this morning and found whole buds munched through and on some flowers 'it' has nibbled off just the ends of the petals.  I found a very large caterpillar on one flower.  It was about 1 1/4" long, grey with a creamy yellow underbelly.  I've never seen it before.  Any clues anyone please?  Said caterpillar has now been 're-homed' on the bird table.  Thanks very much.

Can't help with the caterpillar but have you also double checked that you don't have earwigs?

Angle shades caterpillars can be green or brown