Death's Head Hawk Moth Caterpillar

Acherontia atropos is a large hawk moth with a wingspan of 90–130 mm (about 3.5 to 5 inches), being the largest moth in some of the regions in which it occurs. The adult has the typical streamlined wings and body of the hawk moth family, Sphingidae. The upper wings are brown with slight yellow wavy lines; the lower wings are yellow with some wide brown waves. It rests during the day on trees or in the litter, holding the wings like a tent over the body.

http://en.wikipedia.org/wiki/Acherontia_atropos