In the 40-page Power Ponies story of My Little Pony Annual 2014, the Mane-iac forms a "league of villainy" with several other Maretropolis super-villains, including Pharaoh Phetlock, Long-Face, High Heel, Smudge, and Shadowmane.
Together, the villains defeat the Power Ponies and drain their superpowers.
When Twilight Sparkle and friends are transported to Maretropolis as the Power Ponies, they have to defeat Mane-iac and save the city in order to return home.
This action angers Saddle Rager, transforming her into a powerful muscular pony.
The Mane-iac fires her doomsday device at Saddle Rager, but the beam reflects off Saddle Rager and hits the Mane-iac instead.
She is also portrayed as sadistic and cruel, claiming that the Power Ponies only keep Hum Drum around because they feel sorry for him and calling him useless.
Much like her name is a pun, she often uses puns when she speaks.
In addition, her powers are similar to those of Marvel Comics' Medusa and the way she "walks" with her mane is similar to how Doctor Octopus from the Spider-Man comics moves around with his robotic appendages.