"I shall call the following figure, derived from Jastrow, the duck-rabbit. It can be seen as a rabbit’s head or as a duck’s.” 'Ludwig Wittgenstein
A pack of two die-cast enamel lapel pins, which either appear to be rabbits or ducks, depending on their orientation. The rubber backs to the pins hold them on securely, and you can wear the pins on your lapel, t-shirt, or even your packpack.
The rabbit-duck illusion is known as an ambiguous figure. It can be seen as either animal.
The rabbit-duck illusion is one of many illusions identified by Joseph Jastrow in 1899. In his essay The Mind’s Eye, published in Popular Science Monthly, Jastrow brings the reader’s attention to "a mind behind the eye and the ear and the finger tips which guides them in gathering information, and gives value and order to the exercise of the senses” Our thinking mind, he tells us, makes sense of the world. It chooses our perspective and fills in gaps, sometimes incorrectly.