The Vacanti mouse was a laboratory mouse that had what looked like a human ear grown on its back. The "ear" was actually an ear-shaped cartilage structure grown by seeding cow cartilage cells into a biodegradable ear-shaped mold and then implanted under the skin of the mouse.
The earmouse 
The earmouse, as it became known, was created by Dr. Charles Vacanti and colleagues in the Department of Anesthesiology, UMass Medical Center, Worcester, Mass., USA. and their results were published in 1997. The mouse itself is called a nude mouse a commonly used strain of immunocompromised mouse, preventing a transplant rejection.
The photo of the mouse was passed around the internet, mainly via email, sometimes with little to no text accompanying it leading many people to speculate whether the photo was real. In the late 1990s, the picture prompted a wave of protests against genetic engineering. These claims are false, as no genetic engineering was involved in growing the ear.
In Pop Culture 
The earmouse was also featured in a page of Cage of Eden - a manga (japanese comic) by Yamada Yoshinobu - Chapter 129 page 8.
The earmouse was also featured in an episode of Nip/Tuck (Season 4, Episode 7, "Burt Landau").
Alexis Rockman, an American contemporary artist known for his paintings depicting climate change and genetic engineering, depicted the Vacanti mouse, perhaps erroneously, in his 2000 painting, The Farm.
- USA (2012-05-24). "Transplantation of chondrocytes utilizing a polymer-cell construct to produce tissue-engineered cartilage in the shape of a human ear". Department of Surgery, Children's Hospital, Boston, Mass., USA. National Center for Biotechnology Information. Retrieved 2012-09-14.
- "South Park". Eek, a Penis!.