Prerequisite: 11th-level ArtificerItem: metal circlet or collar (requires attunement)
When worn by a beast with a CR equal to or less than your
Intelligence modifier, this magical collar allows the creature
attuned to exert absolute control over that beast.
The collared beast is friendly to you and obeys your orders
completely. In combat you share initiative and it acts during
your turn. It can move and use its reaction on its own, but it
only takes the Dodge action unless you use a bonus action to
order it to take an action from its stat block or another action.
If you can ride the beast then it counts as a trained mount.
At 17th level, this magic collar can control mostrosities.