Purple Wisp

The Purple Wisp appears in Sonic Colors, exclusive to the Wii version. It gives Sonic the Purple Frenzy ability, which allows him to become a berserk chomper that eats anything in its way. It will also increase in size as long as it continues to eat. The Purple Wisp is not actually a Wisp, but a Nega Wisp, a Wisp whose Hyper-go-ons have been drained by Dr. Eggman. This explains why the Purple Frenzy is fueled by consumption.

Appearance
Being a Wisp corrupted by Dr. Eggman's evil control, the Purple Wisp has a more menacing look than the other Wisps. It has three tentacles stemming from its pointed head, which only has a jack-o-lantern style mouth on it. It is the only Wisp not to have eyes.

Trivia

 * According to the Sonic Colors website, the Purple Wisps are Wisps who were captured, transformed and turned violent by Dr. Eggman and are forced to do his bidding. These kinds of Wisps, which also include the Violet Wisps, are also known as Nega Wisps.