Arctic Bulette

Standing Leap. The bulette's long jump is up to 30 feet and its high jump is up to 15 feet, with or without a running start.

Multiattack:  If a creature is knocked prone by Deadly Leap the Bulette may make a Bite attack against that creature.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 30 (4d12 + 5) piercing damage.

Deadly Leap. If the bulette jumps at least 15 feet as part of its movement, it can then use this action to land on its feet in a space that contains one or more other creatures. Each of those creatures must succeed on a DC 16 Strength or Dexterity saving throw (target's choice) or be knocked prone and take 19 (4d6 + 5) bludgeoning damage plus 14 (3d6 + 4) slashing damage. On a successful save, the creature takes only half the damage, isn't knocked prone, and is pushed 5 feet out of the bulette's space into an unoccupied space of the creature's choice. If no unoccupied space is within range, the creature instead falls prone in the bulette's space.

Cold Breath (Recharge 5–6). The bulette exhales a blast of freezing cold in a 20-foot cone. Each creature in that area must make a DC 14 Dexterity saving throw, taking 22 (5d8) cold damage on a failed save, or half as much damage on a successful one. If the save fails by 5 or more, that creature is restrained as it finds itself frozen in place, covered in ice. A creature can end this effect by spending an action to chip away at the ice ending the effect.