Is it a caterpillar?

Is it a caterpillar?

Observation - Is it a caterpillar? - UK and Ireland. Description: We assumed this was a caterpillar, but can't find it on any identification websites. It was about 3 cms long with a red head waving about. Long black and yellow stripes. C

We assumed this was a caterpillar, but can't find it on any identification websites. It was about 3 cms long with a red head waving about. Long black and yellow stripes. C