Help with adding flags

#1

I’m trying to add the revives flag to every animal in the game. Do I need to write any other code beyond copy from and extends (ex. stats or harvest flags)? For example:

{
    "id": "mon_bear",
    "type": "MONSTER",
    "copy-from": "mon_bear",
	"extend": {"flags": [ "REVIVES" ] }
},