Dark Gaia minions
From Sonic Retro
Dark Gaia minions are enemies faced by Sonic the Werehog during Sonic Unleashed. These supernatural monsters are fragments of the hyper-energy organism Dark Gaia, which fell apart at the beginning of Sonic Unleashed. Doctor Eggman used the power of the Chaos Emeralds to crack open Sonic's world in an effort to wake the beast and harness its energies, but this premature wakening rendered Dark Gaia unable to support itself, instead collapsing into innumerable Dark Gaia minions.
Bizarre, varied creatures of shadow-black and multicoloured neon, the Dark Gaia monsters only come out at night. Ranging from tiny Rex and Dark Fright pests to towering, destructive Big Mothers and Titans, these foes attack Sonic in night-time levels. In addition, they terrorise the human population on a psychological level, directly inducing despair and negative emotions. They even go so far as to posess townsfolk on occasion. The larger minions, from the Nightmare upwards, tend to have stretchy, extensible limbs to grab at their foes. Sonic the Werehog is a partial Dark Gaia monster himself, absorbing a significant dose of Dark Gaia's energy via feedback from Eggman's laser. This contributes to his fearsome night-time appearence, as well as granting him the characteristic stretchy arms. Defeating the minions releases a glowing haze - which Chip calls "Dark Gaia Force" - that increases the Werehog's Unleash gague. This is along with the Chaos Orbs - yellow diamonds that increase Sonic's EXP.
Eggman himself is responsible for getting rid of most of the Dark Gaia minions, hatching a plan in the middle of Unleashed to attract them all together in order to rebuild Dark Gaia as a single entity. When Perfect Dark Gaia is defeated and the beast sent back to sleep at the end of the game, it has re-absorbed all its fragments.