Mane-iac

The Mane-iac is an antagonist who appears in Power Ponies. She has a bluish-purple coat, a mane consisting of large, green tendrils, and green eyes with red pupils.

Depiction in the series
The Mane-iac is stated to be a super-villain in a comic book world that Spike and the Mane Six end up in, and they have to defeat her in order to escape. In an image from the episode released in promotional material, Spike holds up the comic book that The Mane-iac appears in, with pages that show that she gained her super powers (and possibly also became evil at this time) when she fell into a vat of green liquid and was electrocuted by a downed power line. Prior to this, she appeared to be a normal pony with blueish hair, blue eyes, and a pink coat. After climbing out of the vat, she appears to steal an orb from under a glass display case (setting off an alarm), which she uses later in the episode against the heroes.

Quotes
"Power Ponies! [laughs] How kind of you to join us! [evil laughter]"

- Power Ponies animatic