Do You Have to Have a Ring on to Summon Cows?

There's a necromancy spell in here for druids at their level. I can make a face spirit appear in the form of beasts and they appear in an unoccupied space that I can see within range. Do you have to have a ring on? I think you're better off summoning cows. There was another like homebrew D&D thing that I saw on Reddit where some guy was able to like make cows appear. So then he just started dropping cow bombs because they were like, it was something about the z axis toward the rules allowed it. Sounds like the movie twister.