Ash-Bringer

Keen Senses. The tyrannosaurus has advantage on Wisdom (Perception) checks that rely on sight or smell.

Attack the Vulnerable. As a bonus action the tyrannosaurus can move up to its speed or jump a distance up to half its speed toward a target it can see that is dead, incapacitated, prone, restrained, stunned or unconscious, and make a single weapon attack against it.

Siege Monster. The Tyrannosaurus deals double damage to objects and structures.

Wounded Fury. While it has 40 hit points or fewer, the Tyrannosaurus has advantage on attack rolls. In addition, it deals an extra 18 (4d8) damage to any target it hits with a melee attack.

Multiattack. The tyrannosaurus makes two attacks: one with its bite and one with its tail. It can't make both attacks against the same target.

Bite. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 55 (7d12 + 10) piercing damage. If the target is a Huge or smaller creature, it is grappled (Escape DC 27). Until this grapple ends, the target is restrained, and the tyrannosaurus can’t bite another target.

Tail. Melee Weapon Attack: +17 to hit, reach 15 ft., one target not grappled by the tyrannosaurus. Hit: 31 (6d6 + 10) bludgeoning damage. If the target is a creature, it must succeed on a DC 27 Strength saving throw or be knocked back 25 ft. in a straight line and fall prone.

Kick. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 19 (3d6 + 9) bludgeoning damage. If the target is a prone creature, it takes an additional 7 (2d6) bludgeoning damage.

Swallow. The tyrannosaurus makes a bite attack against a Large or smaller creature it is grappling. If the attack hits, the creature is swallowed, and the grapple ends. The swallowed creature is blinded and restrained, it has total cover against attacks and other effects outside the tyrannosaurus, and it takes 18 (5d6) acid damage at the start of each of the tyrannosaurus' turns. If the tyrannosaurus takes 40 damage or more on a single turn from a creature inside it, the tyrannosaurus must succeed on a DC 23 Constitution saving throw at the end of that turn or regurgitate all swallowed
creatures who fall prone in a space within 5 feet of the tyrannosaurus. While the tyrannosaurus isn't incapacitated, it can regurgitate the creatures at any time (no action required) in a space within 5 feet of it. The creatures exit prone. If the tyrannosaurus dies, swallowed creatures are no longer restrained by the tyrannosaurus and can escape from the corpse using 15 feet of movement, exiting prone.

Breath Weapon (Recharge 5-6). The dinosaur uses the following breath weapon.

Fire Breath (Recharge 5–6). The dinosaur exhales fire in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 63 (18d6) fire damage on a failed save, or half as much damage on a successful one.

The tyrannosaurus can take 2 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. The tyrannosaurus regains spent legendary actions at the start of its turn.

Rampage. The tyrannosaurus moves up to its speed or jumps a distance up to half its speed. The tyrannosaurus then makes a single attack. If the target is a structure, this attack deals double damage.

Spot and Track. The tyrannosaurus makes a Wisdom (Perception) check. Until the end of their next turn, each creature the tyrannosaurus detects with this ability check has disadvantage on the next attack roll against the tyrannosaurus.