Chimpanzee Enos pictured wearing a space suit and lying in his flight couch as a handler holds his hands. He is being prepared for insertion into the Mercury-Atlas 5 capsule.
NASA
1961-12-18
<a rel="nofollow" class="external free" href="http://spaceflight.nasa.gov/gallery/images/mercury/mercury_ov/html/s61-04398.html">http://spaceflight.nasa.gov/gallery/images/mercury/mercury_ov/html/s61-04398.html</a>