Mobile. Reindeer can take the Disengage action as a bonus action.

Gore. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 3) piercing or slashing damage.

Charm. One humanoid the reindeer can see within 30 feet of it must succeed on a DC 12 Wisdom saving throw or be magically charmed for 1 minute. If the target suffers any harm, it can repeat the saving throw, ending the effect on a success. If the target successfully saves against the effect, or if the effect on it ends, the target is immune to this reindeer's Charm for the next 24 hours.

The reindeer can have only one target charmed at a time. If it charms another, the effect on the previous target ends.