Never, NEVER, Make a Moose Angry

Alaska Moose Brings Down Helicopter

(And he didn't need the help of his trusty buddy, the flying squirrel>)

The helicopter was trying to herd the tranquilized moose, keeping it in an open area away from open water, but the moose was having none of that! Sadly, while the moose won the battle it lost the war. The tail roter injured the moose sufficiently that the moose had to be put down.