Skull illusion painting by Tom French
Memento mori is a Latin phrase meaning ‘remember you must die’. Memento mori paintings often contain a skull but can contain other symbols such as hour glasses or clocks, extinguished or guttering candles, fruit, and flowers.
The paintings were part of a medieval Latin Christian practice of reflecting on human mortality and that things we chase after during life are left behind when we die.
Vanitas, which means emptiness in Latin, are similarly themed paintings, often from the Netherlands. They were intended to remind the viewer of the transient nature of life and the futility of pleasure, which provided a moral justification for painting attractive objects.

“To This Favour” by William Michael Harnett 1879

“All Is Vanity” by Charles Allan Gilbert 1892
The drawing is a visual pun. The woman is admiring herself in a mirror which appears to be a human skull. In art, a woman preoccupied with admiring her beauty has often been a symbol of vanity. The table where she sits is often called a vanity. The phrase “All is vanity” comes from Ecclesiastes 1:2 (Vanity of vanities, saith the Preacher, vanity of vanities; all is vanity.)
It is less widely known that Gilbert was an early contributor to animation.
Modern Examples

“Vanitas: Flesh Dress for an Albino Anorectic” by Jana Sterbak 1987
