The Wicked Willow of Withywindle

[Boromir88]

I don't think Old Man Willow is a Huorn, I simply think he was a nasty-spirited tree. Of course in reality, a tree won't try to trap you and gobble you up, but we are talking about Tolkien's world, where typically inanimate things can have a spirit, whether for good or evil. Was Caradhras a normal, just very nasty storm? Or was there a dark, evil will that was trying to hinder the Fellowship, for the sport of it? Were those 'normal' wolves looking for some food that attacked the Fellowship? Gandalf didn't think so.

Old Man Willow was a tree, just a down-right mean one:

"...and in it there lived yet, aging no quicker than the hills, the fathers of the fathers of trees, remembering times when they were lords. The countless years had filled them with pride and rooted wisdom, and with malice. But none were more dangerous than the Great Willow: his heart was rotten, but his strength was green; and he was cunning, and a master of winds, and his song and thought ran through the woods on both sides of the river."~The Old Forest

The fathers of the fathers of trees...doesn't that make him a tree? He wouldn't be a pumpkin.

This also gets you thinking about Morsul's #2. He was obviously an old tree, and a po'ed one because the trees were no longer great "lords." So, when little halflings stroll in to take a nap, the prideful, cunning, nasty tree wants revenge.

And in Letter 212:

The Fall or corruption, therefore, of all things in it and all inhabitants of it, was a possibility if not inevitable. Trees may "go bad" as in the Old Forest...

"Corruption" re-occurs throughout Tolkien's books, and not just in living, animate people, but everying in and of Middle-earth can become corrupted. This includes trees, which are different from Huorns, as well as arguably mountains deciding to "go bad."