Monster of the Day: Daleks

Source:  Dr. Who
Location:  Nearly all of space and time
Description:  They have been likened to big pepper pots.  A Dalek is a mutated creature, originally humanoid, now encased in an all purpose battle armor.  In effect it is a cyborg as it cannot really live without its armor.  The armor itself is oddly designed and seemingly a host to a bunch of design problems.  Stairs for example would seem to be a problem.  Don't. Be. Fooled.
Threat Assessment:  Originally around 5.  They get a lot with a positive negative attitude.  Their whole ethos can be summed up in their famous phrase.  "Exterminate, exterminate."  They are clever and armed with high tech weapons.  In the second series of Dr. Who they go all they up to 9.5.  One single Dalek takes out the western US power grid and sucks up the internet.  Their weapondry is upgraded, as is their armor.  They are so technically superior they are capable of making void ships:  Ships that have no mass, or any other physical property that are capable if ripping holes through the universe to parallel universes.
Weaknesses:  A dalek is single minded and is blinded by their own sense of superiority.  Also, in the second series the Daleks were nearly completely destroyed leaving only a few to still scourge the universe.