Cuthbert

My caterpillar's yellow
with splodges of black.
Whenever it crawls
it arches its back.

Then it straightens
till its splodges of black
all lie in a line
on its yellow back.

Each time it moves
it does the same.
I really wish
I knew its name*.

© Celia Warren 2020

For now, I'm calling it Cuthbert, but can anyone help identify this little critter, please? It was very small -- much smaller than last week's Oak Eggar and Drinker -- and not hairy.

*EDIT: My brother has just supplied its name -- it's a Magpie Moth caterpillar -- Abraxas grossulariata.