Quickwood

A quickwood, or spy tree, is a great hardwood that passes for an oak. Only up close does its secret show: a warped humanlike face with eyes, ears, nose and mouth set in the bark. Unless an observer stands within ten feet, there is a 90% chance the face goes unnoticed.

Shifting its huge trunk is hard, so the tree prefers to stay motionless. Instead it sends thick roots snaking through loose topsoil at 30 feet per round, out to 90 feet. A root can grip and immobilize any creature weighing less than 1,000 pounds and drag it to the maw in a round. Roots deal no damage themselves. They cannot be broken and ignore blunt weapons, but edged ones can cut them; each counts as a Large creature with 10 hit points, and damage to roots does not count against the tree. After six roots are severed, it pulls the remaining 1d6+6 back to safety.

Its branches are too rigid to fight with, but the mouth snaps shut for 3d4, provided the victim is touching the trunk or has been hauled into reach by a root. Its senses beat a human's slightly, it has 120-foot infravision, fine rootlets spread out to feel approaching footsteps, and its leaves sense shifts in air pressure and movement.

Plant-affecting spells work on it; most others do not. It sweats water to soak itself against fire, grounds lightning harmlessly, and ignores poison, gas and mind-affecting magic. A successful disintegrate destroys it. When targeted by a spell it radiates fear in a radius of 10 feet per spell level. If the caster fails a saving throw, all the spell's energy goes into the fear; on a success the fear is just a byproduct and the spell works normally, saves still allowed.

A mature quickwood can possess 2d4 ordinary oaks within one mile, which sprout faces and senses through which it watches and controls them.

Quickwoods grow anywhere ordinary oaks do, including warm lands with live oaks. They can be charmed or persuaded to hold treasure, which reflects whoever placed it and is always tucked inside the trunk, or to stand guard, spying for intruders and sounding a hollow drumming audible a mile or more away.

Some say these trees exist only because a mighty wizard, or perhaps a druid, enchanted mandrake roots with powerful spells and planted them. Others think they mark plant life's natural climb toward awareness and movement. Either way, unlike almost all vegetation, quickwoods are truly sentient.