Charge. If the dolphin moves at least 30 feet straight toward a target and then hits it with a slam attack on the same turn, the target takes an extra 3 (1d6) bludgeoning damage.

Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make Constitution saving throw with a DC of 5+ the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hp instead.

Immunity. Poisoned condition

Resistance. Poison damage

Slam. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage.