Some trees are perfect - perfect shape, perfect size, perfect color. They do their jobs very well and as people we enjoy them. Some trees, however, have a style all their own and make us pause and really consider them. And then there are snags. Snag trees are dead, dying, broken down trees that somehow are still standing. This is the tree that you know is haunted. You don't want to meet it in a dark alley. Ichabod Crane ran pell mell away from this baby.
Snags, however, provide imporant habitat for wildlife. My in-laws have let an old weeping willow gradually decay and (literally) fall apart. It provides shelter for a huge variety of bird life, so they have made the choice to leave it standing, and enjoy all the birds it houses. We are taking bets on how long it lasts, but it may yet surprise us.