Corrupted 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.

Avoidance. If the bulette is subjected to an effect that allows it to make a saving throw to take half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Displacement. The bulette projects a magical illusion that makes it appear to be standing near its actual location, causing attack rolls against it to have disadvantage. if it is hit by an attack, this trait is disrupted until the end of its next turn. This trait is also disrupted while the bulette is incapacitated or has a speed of 0.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 30 (4d12 + 4) 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 14 (3d6 + 4) 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.

Tentacle. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 7 (1d6+4) bludgeoning damage plus 3 (1d6) piercing damage.