Half-Life: Alyx Workshop Tools/Level Design/Runner Headcrab

Setup

Create a test room. Insert a npc_headcrab_runner this will spawn the runner head crab, in order to allow it to revive entities you have to enable NPC Properties > Can Be Revived on each npc_zombie that you will be revivable. You can also use Reviver Group in order to specify which runner headcrab can revive which zombies.

Finishing up

Compile and run your map, and you should have a working Runner Headcrab along with zombies that can be revived