Barf. The Z-Rex begins combat with 3d12 + 8 zombies stuck all up inside it. Whenever the Z-Rex makes a Bite attack, whether it hits or misses, it expels 1d10 + 3 zombies. The zombies enter the initiative order immediately following the Z-Rex.

Undead Dinosaur Fortitude. In addition to the regular Undead Fortitude rules for dropping to 1 HP instead of 0, whenever the Z-Rex takes damage, it must make a Constitution saving throw with a DC of 10+the damage taken, unless the damage is radiant or from a critical hit. On a success, the Z-Rex has resistance to that instance of the damage

Multiattack. The tyrannosaurus zombie 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: +10 to hit, reach 10 ft., one target. Hit: 33 (4d12 + 7) piercing damage. If the target is a Medium or smaller creature, it is grappled (escape DC 17). Until this grapple ends, the target is restrained and the tyrannosaurus zombie can’t bite another target or disgorge zombies.

Tail. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage.

The Z-Rex can take 3 legendary actions, using the options below. It can take only one legendary action at a time and only at the end of another creature’s turn. The Z-Rex regains spent legendary actions at the start of its turn.