I always took the "walking tree" to be an
entwife. Here's why:
1.
Treebeard and the
ents haven't been up that way for a LONG time (so he tells
Merry and
Pippin) but from the way they describe
the Shire the
Entwives would like it.
2. I doubt they would go to
the old forest since Entwives preferred gardens and orchards to forests, thus they would like land like the shire.
3. The
north kingdom was destroyed and no one roamed the lands north of the shire, except the occasional
ranger going to the remains of Fornost. So the Entwives would have some safety in isolation.
4. There is some doubt as to whether any Entwives escaped. So if this were the case, the story would have a nice bit of closure in that the ents may finally find the entwives in the
fourth age as
King Elessar opens the lands that were formerly closed to the ents.
5. And finally I recall either in the appendices or in Unfinished
Tales that the
Rohirrim occupied
Rhovanion (the area between
Mirkwood and
Anduin (and adjacent to
the Brown Lands on
the one side and
Fangorn on the other side of the Anduin) and on eastern Mirkwood. It is also near the place of origin of the
Hobbits (thus the similarities in speech and customs, and how the Rohirrim seemed to be the only people who had any tales of Hobbits). This all seems to be very coincidental. Could it be that when the Hobbits crossed the
Misty Mountains, maybe the surviving entwives did as well?
Eol