From Valve Developer Community
From the Mod Corner:
Did we mention you also get to save the world by blowing up aliens and taking out giant robots?
Hey, when do you ever take out giant robots (other than for a walk, eg. Dog)?
- Hmmmm... Walking Dog... This intriges me. Perhaps with Alyx? --JeffMOD 14:36, 4 Apr 2008 (PDT)