A PC mod that replaces the model is already available.
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You've probably seen the in-game model "Corpse01.mdl" if you've played Half-Life 2 or Source engine mods. The burned corpse appears several times in Half-Life 2's sewers and other locations. Turned out, the corpse face model is a rendering of an actual corpse taken from a medical book.
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NSFW WARNING
Furthermore, the discovery was later shared on YouTube and Twitter by YouTuber Richter Overtime. As you'd expect, many Half-Life fans were shocked to discover that they had been staring at a real corpse for the past two decades.
The burnt corpse from GMod is a real body (via/ Richter Overtime)
It is still unclear whether "Corpse01.mdl" is based on this actual corpse, but these findings appear credible. Also, there is already a PC mod that replaces the model with a composite of Dr. Kleiner and Breen's faces if you want to play Half-Life 2 without having to think about any of that.
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