The Antimattercorn is a pegasus scientist who invented a head-mounted generator that fires beams of supremely destructive antimatter. She leads the rest of the team and makes the plans, but quickly loses her temper when things go awry. She can't stand her teammates, finding them terribly frustrating and unreliable, but stays with them because they can't accomplish much on their own.

Her real name is Exacter "Ex" Nihilo, her teammates often using her nickname. She is a talented inventor despite not having unicorn magic, and though she may never admit it, might hold a jealousy or general rivalry of unicorns. In her base of operations, she has devised a workbench of delicately articulated spider-like graspers controlled by expertly controlled wingfeather movements, which allow her inventions to surpass the crafting potential of the normally unparalleled fine-tuning capabilities of unicorns.

The reason she's a pegasus with a mechanized horn is because I made her before the comic came out and confirmed Matterhorn is a unicorn. We only knew her as Twilight (an alicorn) so this was my way of sorta covering my bases. She's the most "classic" of the villains, a pretty standard "evil genius with a death ray" but they really work and make great leaders.