Timmy. Considering the host segments involving him are a homage to Aliens, its expected.
He's even scarier in the theater. He just sits there and you know he's going to do something. Yeah, it's distracting from the film, but still! He keeps bothering Servo until he's annoyed, then chokes him, and drags him out of the theater whilst we can hear Servo's muffled sobs and cries for help. This doesn't last long, though.
In the movie, Dr. Forrester turns off the oxygen to the satellite and Mike is suffocating to death.
Seeing Crow partially melted in the first segment from "The She-Creature" from using the Thaw Master, mistaking it for the Thighmaster.
In the "local color" sketch from The Amazing Transparent Man, Mike (as the crazy "Mikey") doesn't blink for about an entire minute on camera.