Terrahorn is one of the Legendary Monsters. He can be summoned at Earth Sanctuary on Earth Island. His name originates from the words "terra", meaning ground, and "horn".
Terrahorn can be unlocked or "restored" by collecting all 5 earth stones.
Spirit Crush : 130 power, unlocks by default
Arkane Spikes: 150 power, unlocks at level 12.
Ancient Tendril : 200 power, unlocks at level 25.
Stunning Strength : Attacks have a chance to stun. Unlocks at level 35.
AfterShock : While using a skill, tap enemy for additional damage. Unlocks at level 35.