Trolls, despite their appearance, are the most efficient creeps, being both easy to creep and very rewarding. The Trolls will always aim for your heroes, often wading through entire battalions to get to them and suffering trample revenge damage. This means that you can easily lure the troll through one or more battalions on aggressive stance to have it suffer heavy damage before turning around with your hero to attack when it turns around. This almost always guarantees an easy kill if well executed. Of course, pikes will make it much easier using this strategy, but even Orc Warriors can kill a troll using this tip. After that destroying its lair is easy and yields a high reward.