The Reindeer Leash is classified as a limited rare toy that connects the player with their equipped pet. As it was a prize on the Adopt Me! 2019 Advent Calendar for 2019 Christmas, it is no longer obtainable unless though trading with other players. When you have a pet equipped, this leash will have a pink string leading to the pet you have equipped. It is similar to the Mouse Leash and Dog Leash. It has no effects on any pets since it’s just a leash.