Or whatever you might translate Jack as: Johannes, Jakob or perhaps even Joachim. Although I think Jack Rabbit is used for the American version rather than our Lepus europaeus.
An extremely rare sight in our parts. I would count myself lucky to see one a year and that despite being out virtually every day on countryside walks.
Our landscape is not suited. We have too much forest (for foxes) and too few hedges alongside arable fields for them to hide. To an extent, in the summer they can use the maize fields when they are tall enough, as this one is doing -in the background.