Trident of Fish Command
Weapon (Trident), uncommon, requires attunement · 2024 rules, SRD 5.2
This magic weapon has 3 charges, and it regains 1d3 expended charges daily at dawn. While you carry it, you can expend 1 charge to cast Dominate Beast (save DC 15) from it on a Beast that has a Swim Speed.
Also in the 2014 rules (SRD 5.1).