The caterpillar of the Great or Common Eggfly butterfly is black with a red head and very spiky.
Spikes are arranged in (part) rings around the body, unlike the Page/Malachite caterpillars where the spikes are in longitudinal rows.
The caterpillar starts out wholly black and develops a dark red head with its black spikes. The spikes
lighten to red.
The head becomes brighter red and the spikes become orange.
The spikes become orange-yellow before pupation.