Aldinach's Bulette

Standing Leap. The bulette's long jump is up to 50 feet and its high jump is up to 25 feet, with or without a running start.

Aldinach's Caress. When Aldinach's Bulette moves into any space shared by, or adjacent to, a large or smaller creature, black tendrils of Abyssal ichor reach out from the Bulette and attempt to grapple each creature. Targets must successfully contest the Bulette's Strength (athletics) check with a Strength (Athletics) or Dexterity (Acrobatics) check of their own. On a failed check, the tendrils engulf the creature and the creature is considered grappled. It also immediately suffers from Aldinach's Kiss. 

When the Bulette moves, any creature engulfed in Aldinach's Caress moves with it,  if the caught creature is willing or incapacitated. If it is not willing, the creature is released from Aldinach's Caress.

Only one creature may be engulfed at a time. An engulfed creature can try to escape Aldinach's Caress by using an Action to contest the Bulette's grapple. 

Aldinach's Kiss. When a living creature grapples or is grappled by Aldinach's Bulette it takes 4d6 necrotic damage. This damage is repeated at the beginning of a grappled or grappling creature's turn, and the Bulette's turn until said condition ends.

Aldinach's Succor. When an undead creature or demon grapples or is grappled by Aldinach's Bulette, the Bulette regains 1d8 + 7 hit points.

Bite. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 50 (7d12 + 8) 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 18 Strength or Dexterity saving throw (target's choice) or be knocked prone and take 26 (6d6 + 8) bludgeoning damage plus 26 (6d6 + 8) 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. Each creature is then immediately subject to Aldinach's Caress.