Bizarre Alien Biology: Their new forms have many odd traits for how they live in the Big MT.

Klein in particular - are the real instance of this trope in Old World Blues, and not Dr. As hilariously endearing as they are, he is not wrong to fear them.

Beware the Silly Ones: Ulysses of all people fears the Think Tank.

Mobius believes in containing them by any means necessary.

Ax-Crazy: They enjoy ruthless and unethical experimentation, either due to them being unable to understand the dangers that they pose or because the experiments will result in destruction.

Since their experiments blew the entire top of the mountain off many years ago, those who come across it instead read it as the 'Big Empty'.

Artifact Title: The Big MT, their base of operations and research, meant 'Big Mountain' due to being located inside of one.

Artistic License Biology: As a whole, the group tend to hold rather bizarre perspectives on human anatomy, especially given Klein's belief that fingers and toes are penises.

They will be the first group of people - for a given value of 'people' - the Courier will meet after entering Big MT. That was a long time ago, and they have very much gone to seed as brains in jars.

The pre-War head scientists of Big MT, who were among the finest scientific minds of their generation.

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