Groundshaker

Groundshaker is a boss from Kingdom Hearts II.

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

Atop the beast is an unnamed witch doctor Heartless who resembles a Shaman. Similar to the Shaman and the Living Bone, the witch doctor forms a symbiotic relationship with Groundshaker. When the witch doctor's double-mask rotates, 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. Timon hints that the witch controls the beast. It is entirely possible that they are one in the same, as the witch doctor sometimes merges with the beast. However when it dies the Shaman is the only one seen to vanish and a heart pop out. It is easy to tell what earlier Heartless inspired Groundshaker--he has uncanny resemblance in attack style to Behemoth from Kingdom Hearts.

Strategy
The main thing to remember is that you only have to attack its eyes, as well as the shaman-like Heartless on its back. At the start make use of the Reaction Command to stun the Groundshaker. After this, enter into a combo attack and use Simba's limit.

Soon you will have the chance to jump on its back, using the Reaction Command Jump. Attack the shaman. Once it reaches low health it will inflame its eyes and run. Repeat the first few steps.

When it is upright again on the Groundshaker's back the Shaman can go invisible and use Fire-like attacks (or Thunder-like attacks). Use combo attacks (and if possible, Simba's limit) until all its HP is depleted. Like all other boss battles, heal when necessary.

NOTE: When you fall off the back jump up the leg to get back on.

When attacking the eyes you can do two things: first, you can use magic attacks. The best magic attacks to use are the elemental ones - Fire, Blizzard and Thunder. Casting magic whilst locking on to the eyes should keep it down.

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

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

Trivia

 * It is believed that Groundshaker is the largest Heartless that Sora ever fought (excluding World of Chaos).
 * Based on the beta screen shots, many fans believed that Behemoth would appear in Kingdom Hearts II. It did, only in the Battle of 1000 Heartless, but it could not be fought. Instead, Groundshaker took Behemoth's place as a boss battle.