Allowed to build when you have the level 3 Underhall, and does damage to any hostile monsters around it. (Info only based on 3rd Underhall)
Mostly weak monsters like finks,Bolt,and pokeys will be destroyed in one hit, so stonger monster such as Crabatrons or Daves is recomended,still it can kill in two hit like Zagnoid and Spurtz so use stronger monsters.
NOTE:It can't hit a digging monster in the underground like Valgos,Wormzer, and King Wormzer. It can be build in both the backyard and the Inferno, but it always costs inferno resources. You HAVE to have an Inferno base. Defeat all Moloch's bases to unlock your own Inferno base.
Has a very massive damage.Costs ABOUT 300,000 bone, 200,000 coal, and 125,000 sulfur.The Damage is about 3000. Buffed Monsters can withstand 50% of the damage.Has 2000 damage after it is half destroyed.
TIP:Very effective when facing monsters in groups. (such as 100 pokey) The waves it uses travels though the ground damaging everything it touches. Try to put monsters seperatly. (such as 2 pokey and 2 crabatons after that)
HINT:After building a quake tower make sure to keep it near resources. Most people need resources, so they attack them.