The Ghost Kraken is a giant, robotic octopus. It is purple with a yellow jewel and stripes around it's body, white ones on its legs and rest being gray. It also has glowing green eyes. Its color scheme changes each time it is hit.
After Sonic encounters Captain Whisker and meets Blaze again, Captain Whisker sends the Ghost Kraken on the two to destroy them.
The battle with the Ghost Kraken take place on a circular plane. During the fight, the Ghost Kraken attacks mostly with its tentacles. The normal tentacles can be hit, causing no damage, but there is one jewel-like tentacle, which is its weak spot. Hitting the other tentacles will only make the Ghost Kraken mad quickly. At times, it will also launch globs of ink which will temporarily stun Sonic or Blaze and it will slam its tentacles down on those areas as well.
As the fight progresses, the Ghost Kraken will start to grow enraged and will submerge the platform underwater. While underwater, the rest of the platform is blocked off and the player can't jump over the tentacles. Also, it may spray a jet of ink to cloud the player's vision, and it will send the tentacles in waves. At that time is the chance to hit its weak spot. At the end of the fight, the Ghost Kraken will fire a glob of ink directly at the screen, almost completely clouding the player's view. The Kraken will then bring all its tentacles out and the player has to hit the tentacle with the crystal to finally defeat it. Luckily, the player's view isn't completely blocked. The ink can be wiped away by the stylus, but this method takes longer.
The way the platform on this boss is similar to fighting Egg Turtle.
Like the mentioned boss fight, the player cannot drown while submerged underwater.
Although referred to as an octopus, while fighting the Ghost Kraken it can only be seen using six different tentacles at a time.