Trolls are giant bosses that can be destroyed by S tier dragons and higher. The amount of times necessary to hit them with boost attacks varies with size tier. They spawn in different places, although most of them are scripted. These enemies are very strong and can be very dangerous to xs dragons. They mainly attack with their club by swinging it down in an attempt at hitting the player, or by stomping. Their club swing can hit the player's dragon if they are above the troll.
Trolls will attack the player on sight if they are in their aggro zone. They won't chase the player, but rather stay still and defend their ground.