Indestructible. Immune to player card effects.

Forced: When Old Man Willow attacks, discard a random location from the victory display. The defending player raises his threat by X, where X is that location's victory point value.

While Long Trailer is in the staging area it gains:"Forced: After the active location leaves play as an explored location, Long Trailer makes an immediate attack against the first player."

"Occasionally the most unfriendly ones may drop a branch, or stick a root out, or grasp at you with a long trailer." –Merry, The Fellowship of the Ring

Forced: After Grasping Root engages a player, that player must assign X damage among characters he controls. X is the number of locations in the victory display.

...a great tree–root seemed to be over him and holding him down... –The Fellowship of the Ring