The subject of this article or section originates from non-canonical sources. To find out about what is considered "canon" see LOTR:Canon.
"Attack Troll" is the term given to the elite trolls (Olog-hai) of Mordor who invaded Minas Tirith in Peter Jackson's The Lord of the Rings: The Return of the King. They are distinguished by their armor, horned helmets, and massive spiked clubs. They are perhaps the most powerful troll seen in the films.
The Lord of the Rings: The Return of the King
In the third film, Attack Trolls appear immediately once Grond has broken the gates of Minas Tirith, entering and attacking the ranks of defenders alongside hundreds of orcs. They send multiple soldiers of Gondor flying with a swing of their weapon, and resist showers of arrows. Gandalf the White is shown to slay one of them, using both his staff and Glamdring.
The Lord of the Rings: The Battle for Middle-earth II
In Electronic Arts' RTS computer game The Battle for Middle-earth II and its expansion, Attack Trolls are available to the Mordor faction, and of all offensive units are strong against the largest variety of things: structures, cavalry, swordsmen, and archers.
The Lord of the Rings: Conquest
Attack Trolls appear also in the battle simulation RPG The Lord of the Rings: Conquest. In battle, the player is able to climb up one's back, and kill it by stabbing its neck.