Now that I know where that robot will be, I can destroy MECH-X4 in front of it's biggest fan.
— Principal Grey

Kim Grey was the principal of Bay City High. She appears nice and caring, but in fact is the one deploying the monsters against the city. She was working for Seth Harper, an evil mastermind bent on destruction, but she never knew her boss's identity.  

She is portrayed by Ali Liebert.  


Seth, or the Mastermind, hired Grey to eliminate the MECH-X4 team with monsters in Let's Dig Deep! To protect her identity, Grey chose to be the principal of Bay City High and has been monitoring the team. Grey hired Davage to help her defeat MECH-X4 for the Mastermind.

Grey has been getting closer and closer to destroying MECH-X4 - such as finding out their identity, finding their base and stealing the robot - however, the Mastermind has gotten fed up. He sent Morris in Let's Get the Big Bad! to be an assassin for Grey.

The MECH-X4 team and Grey team up briefly but Grey turns on them and hands them to the Mastermind. When Clawboon attacks, Ryan quickly defeats it so the team could handle Grey. With surprise effect, Grey slipped into Clawboon's ooze which was destroyed by the X-Weapon.

In Versus The New Evil, she was determined to get revenge on the team. As well as this, she got the ability to transform into Clawboon. When she worked out how she did it, she made Traeger. Grey has been under Traeger's command and they've been working together to extinguish the MECH-X4 Team.

In order to power up Traeger and control every person with the Red Bloom, they needed Harris so Traeger was easily capable of controlling Harris. They also controlled Morris so they could get to Seth. In Versus Harris, Traeger, Grey, Morris and Harris launched the Red Bloom into greenhouses and multiplied the Red Bloom to make everyone under Traeger's control.


Monster Form Grey

Grey In Monster Form

She appears to be nice but is actually the one behind the monster attacks. When one of the monsters she created lost a battle to MECH-X4, she became extremely angry, showing that she has a short temper.



Grey created Traeger and formed him. However, Traeger is in control of Grey using the Red Bloom. Ever since Grey and Traeger teamed up against MECH-X4.

Seth Harper

Grey's relationship with Grey is complicated as Grey was once working for Seth, without realizing who he really was and goes by the name "The Mastermind". When Grey found out who he really is, he caught him and used him to make monster ooze. Seth and Grey teamed up with Traeger with Morris to make everyone under the power of the Red Bloom.


Morris and Grey first met in Let's Get the Big Bad!, where "The Mastermind" used Morris to eliminate Grey. Morris and Grey encountered again when they controlled him with the power of the Red Bloom.


  • Monster Desk: Principal Grey has a desk located in her office which allows her to merge two creatures or creatures' D.N.A. together to create a monster. It glows orange when in use, just like the ooze the monsters are made of.
  • Ninja Skills: Principal Grey is very flexible and very good at combat fighting. This was shown when she fought Ryan in Let's Open The Monster Heart!.
  • Monster Ooze: In Versus The New Evil. It is shown she had returned, after falling into Clawboon's ooze. It is also shown that she now can transform from human to a monster, and back. She can also resist a lot of damage.


Season 1

Season 2