Skulls are an acknowledged symbol of death and mortality. The skull represents our physical life now ended.
The image of a snake weaving through the eye socket is very popular with artists in particular tattoo artists. However, it’s meaning is not as dark as it may seem. The snake is symbolic of renewal perhaps because of its ability to shed its skin. When combined with a skull it indicates that there is rebirth and resurrection.
The Death’s-Head Skull, usually a depiction without the lower jawbone, was emblematic of bawds, rakes, sexual adventurers and prostitutes.