This is just a content pack that replaces most Half-Life 2 NPCs, except zombies, with their models and animations from Half-Life 2 Episode One and Episode Two. If you want to have Episodic animations for zombies, I recommend Sabrean's Headcrab Zombie Mod. ...

The zombie model has been officially updated and I don't think you have to use this mod. The new zombie animations come from EP1 and EP2, you will see some uncommon animations, and it is not recommended to use Sabrean's Headcrab Zombie Mod....