Janitors

The janitor is another piece of machinery left behind by the Martians on Mars.

Description
At first one might laugh, since what danger could a janitor be? The laughing stops once this machine goes rabid, since its programming isn't prepared for humans and it comes to the conclusion to dispose of the "trash" with violence. These machines are slow, but very heavily armored and can do serious damage. Now a janitor is no longer something funny at all.

Usually found in the old cities of Mars.