Wheatley Core ( from Portal 2 ;) )

Wheatley is a Personality Construct in the Aperture Science Enrichment Center.

Backstory
Wheatley was created in 1998 by Wheatley Jokryl to stop GLaDOS from flooding the enrichment center, with a deadly neurotoxin. He was created and named "The Intelligence Dampening Sphere". Wheatley was just a codename.

After the sphere's failure, it has been detached from GLaDOS. It is unknown what happend next.

Despite what most people know, Wheatley originally used to be human. Wheatley Jokryll thought he was using one of the template core chips, but instead he accidentally used a Stephen Merchant's (Stephen Merchant was put into a chip).

Enemies

 * GLaDOS
 * Primek
 * Ender

More Information
Wheatley has also taken control of the facility a few times.