Kooy

Kooy was a member of the Black Mesa security team and a good friend of Barney Calhoun. He appears only in Half-Life: Blue Shift.

Half-Life: Blue Shift
Kooy and Barney were planning to go out to a bar after work on the day of the Black Mesa Incident. He and Barney briefly discussed this before Barney was sent to repair an elevator.

While Kooy almost certainly died after the resonance cascade, the way he died is unknown.

Trivia
The only character to offer Barney a beer.