The phrase "dead hare" refers to a lifeless or inanimate hare, which is a type of animal similar to a rabbit. It implies something that is no longer alive or relevant. Full definition
And our view of Beuys is too dependent on a smattering of iconic works whose connectedness can be difficult to discern: scribbled blackboards, felt suits, photographs of the artist lecturing to a dead hare. (artinprint.org)
This great German artist and visionary, who locked himself in a cage with a coyote, planted trees for the future and talked to a dead hare was not only the most charismatic of performers but a master draughtsman. (theguardian.com)
There have always been great exhibitions during the International Festival - I remember Rembrandt, Daumier, Corot, even being taken to see Joseph Beuys lecturing his dead hare when I was a child growing up in the city. (theguardian.com)