Wait... wait. This sort of shit is expected, swapping old school fps player characters.
What in the french fried fuck do you mean "spyro in half life"?
Edit: Of course it's Magic Nipples that's making this batshit crazy stuff happen. Here's the Spyro mod's webpage: https://hlyotd.com/
Duake is more than just replacing the player character and calling it a day, it makes additional edits to Episode 1 of Quake to add more new features and make everything work together more seamlessly, among other things.