Gabe Newell's son inspired the creepy baby at the end of Half-Life

https://www.pcgamesn.com/half-life/gabe-newell-son-half-life-final-boss-nihilanth
Implies hints of things to come. Or maybe we will just have to wait for baby Gray’s game. ;(

I’m kinda looking forward to seeing what this kid cooks up.

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.