Fast Walker

The Fast Walker is a dog-like alien cut from Half-Life - but not an enemy. It never went further than the concept stage and was therefore never scripted, due to a lack of convincing AI and gameplay goals.

Depiction
Highly intelligent, the Fast Walker was supposed to be an ally of Gordon, learning to love him along the way for all the fresh meat he would inadvertently provide through combat. With the help of its six eyes allowing nightvision and heat detection, it would go before Gordon and bark to give the him clues about what was coming around the next corner. He was also to have well developed limbs allowing the use of machinery and weapons.