A tree with a bad attitude, and big enough to kill.
You.
The tree may have started as a thorny thistle, a scratchy shrub, a bothersome bush, a harassing hedge, but then it grew. Oh, yes, it grew. Up.
Way up.
And now it's there, waiting for you to come along, whistling a happy tune, all footloose and fancy-free, whiling away the afternoon hours out in the fresh air, without a care in the world.
Think this is so? Oh, my friend, no. You are so screwed.
Because this tree is gonna getcha.
With a single, sudden, vertical, overpowering whack.
Right on your pointy little head.
And all your planning, your experience, your ultralight this and titanium that, well.
They ain't gonna help one little bit, you stupid putz.
Youse gonna go splat.
And then the tree is gonna eat ya.
Mmmmm. Mmmmm. Tenderized backpacker.
Also known as: a "Hazard Tree", "Widow Maker", "Widow-Maker", "Widowmaker". And so on. (You get the idea.)