A big bore.

A big boar came running towards me at speed close to the speed of light. I gave it a slip and went to sleep. Because of its mind-boggling speed, by the time the thick head realised it had missed the target it was light years away from me. But again considering the speed the damn thing had managed to gather it took him only a couple of minutes to reach within striking distance. Since, I have read somewhere, if something with mass ever managed to imitate the speed the light, it would turn into energy. And if the author of the book had any credibility, it should stop existing and therefore cease to be of any considerable threat to me. But the author of the book forgot to add that that thing has to be reminded that it was time he turned into energy or he stop speeding. So the wild bore chase is still on.