This image seems unassuming at first, I'm sure. It is a detail from Andrea Mantegna's "The Agony in the Garden" (circa 1458-60), in which Christ's apostles have fallen asleep though they meant to keep vigil with him. He entreats a small party of angels with the message that He would much rather this task fall from him, but God's will be done. Is there no living creature awake nearby to keep Him any company? There is - this humble brown rabbit, heading out of the picture frame as if to run for help. For those who want to arrest Him are coming, and all that stands in their way on the road are a few more of this rabbit's kind.
You can learn more about this painting at Britain's National Gallery.