I saw a really funny one of some soldier in Iraq or Afghanistan, got into a pen with a ram, put his helmet on, and continually goaded the ram into butting heads with him!
It was a riot, and you could tell the Afghanis or Iraqis watching thought it was funnier than hell too...
He was a bored guy, far from home, just blowing off steam...then the ram really nailed him a good one nearly driving his helmet down over his eyes...he grabbed the ram by both horns and gave it a big smooch between the horns!