Charles Allan Gilbert better known as C. Allan Gilbert, was a prominent American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 illustrator

Illustrator

An Illustrator is a narrative artist who specializes in enhancing writing by providing a visual representation that corresponds to the content of the associated text...

. He is especially remembered for a widely published drawing (a memento mori

Memento mori

Memento mori is a Latin phrase translated as "Remember your mortality", "Remember you must die" or "Remember you will die". It names a genre of artistic work which varies widely, but which all share the same purpose: to remind people of their own mortality...

) titled All Is Vanity. The drawing employs a double image (or visual pun

Visual pun

A visual pun is a pun involving an image or images .Visual puns in which the image is at odds with the inscription are common in Dutch gable stones as well as in cartoons such as Lost Consonants or The Far Side...

) in which the scene of a woman admiring herself in a mirror, when viewed from a distance, appears to be a human skull. It is less widely known that Gilbert was an early contributor to animation

Animation

Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...

, and a camouflage

Camouflage

Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...

 artist (or camoufleur) for the U.S.