Groundshaker

The Groundshaker is a boss from Kingdom Hearts II.

The Groundshaker is a titanic doppleganger-like Living Bone that roams the Pride Lands after Simba triumphs over Scar's Ghosts. The ghosts all merge to form the gigantic Heartless--easily one of the biggest Sora ever fights, comparable only to the World of Chaos. The top of the beast is very much like a lush Savannah. It is the boss of the Pride Lands on the return visit.

Atop the Groundshaker is an unnamed witch doctor Heartless that resembles a Shaman. Similar to the Shaman, the witch doctor forms a relationship with the Groundshaker. When the witch doctor's double-mask rotates, the Groundshaker's head would also rotate. One side uses volcanic fire attacks, while the other side uses eerie electric magic.

It is unknown whether the beast or the witch doctor is the Heartless named Groundshaker. It is entirely possible that they are one in the same, as the witch doctor sometimes merges with the beast. However, it is easy to tell what earlier Heartless inspired the Groundshaker--it has uncanny resemblance in attack style to the Behemoth from Kingdom Hearts.

The reward for defeating the Groundshaker is an upgrade to Sora's Thunder magic.

Journal Entry
''A giant Heartless that appeared in the Pride Lands. It was created by the many illusions of Scar.''

The main body on the back of the creature controlled its bones, creating chaos in the savannah.

Trivia

 * It is believed that the Groundshaker is the largest Heartless that Sora ever fought (excluding World of Chaos)
 * Based on the beta screen shots, many fans believed that the Behemoth would appear in Kingdom Hearts II. Instead, the end result was the Groundshaker.