Some sounds I adapted and edited for my game based on a basic Godot tutorial. They are adapted from various CC0 sound effects from here:

First set of three ("Hunter" enemy) adapted from -
Camel groans by AntumDeluge:
https://opengameart.org/content/camel-groan

Second set of three ("Bug" enemy) adapted from -
Bat Screeches by AntumDeluge:
https://opengameart.org/content/bat-screeches

Third set of three ("Zombie" enemy) adapted from -
Zombie Sound 2 by Proxy Games:
https://opengameart.org/content/zombie-sound-2

Fourth set of three ("Alien Scout" enemy) adapted from -
Random sound effects by Brandon Morris:
https://opengameart.org/content/random-sound-effects

I for the life of me don't remember what effects I applied in total to the finished sounds, but editing was done in audacity.