The Nega-Mother Wisp is the secret final boss in the Nintendo DS version of Sonic Colours. This is the true final boss instead of Eggman himself as was done in the Wii version of the game. It is unlocked by collecting all of the 7 Chaos Emeralds through the games Special Stages.
The Nega-Mother Wisp is actually Yacker's giant mother, who has been put under mind-control by Dr. Eggman with his mind-control device. This Wisp is not only the mother of all Wisps but also the creator of Planet Wisp. In one of the last cut scenes, Yacker asks Sonic to stop his mother. Then, Sonic transforms into Super Sonic and attempts to destroy the over-sized Nega-Wisp.
The Nega-Mother Wisp starts by attacking Super Sonic with energy blasts. Super Sonic must hit asteroids into the monster. After a few asteroids are hit, Super Sonic charges to strike the Mother's eye, while dodging the energy blasts and lasers the Mother throws. Each time you hit the Mother's eye, two petals fall off. Once all the petals are gone, the Mother will return to her original state, and the fight will be over.
After the fight, the Mother thanks Sonic and Tails for all they have done to save them, and then teleports the planets to their original locations.