Homebrew

Traits

Disgorge Zombie. As a bonus action, the tyrannosaurus zombie can disgorge a normal zombie, which appears in an unoccupied space within 10 feet of it. The disgorged zombie acts on its own initiative count. After a zombie is disgorged, roll a d6. On a roll of 1, the tyrannosaurus zombie runs out of zombies to disgorge and loses this trait. If the tyrannosaurus zombie still has this trait when it dies, 1d4 normal zombies erupt from its corpse at the start of its next turn. These zombies act on their own initiative count.
Undead Fortitude. If damage reduces the tyrannosaurus zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Actions

Multiattack. The tyrannosaurus makes three attacks: one with its bite, one with its tail, and one with its kick. It must make each attack against a different target.   Bite. Melee Weapon Attack: 1d20+11 to hit, reach 10 ft., 4d12+7 piercing damage. If the target is a Medium or smaller creature, it is grappled (escape Athletics/Acrobatics DC 18 check). Until this grapple ends, the target is restrained, and the tyrannosaurus can't bite another target.   Tail. Melee Weapon Attack: 1d20+11 to hit, reach 15 ft., 3d8+7 bludgeoning damage, and if the target is a creature, it must succeed on a Strength saving throw DC19 or be knocked prone.   Kick. Melee Weapon Attack: 1d20+11 to hit, reach 5 ft., 3d6+7 bludgeoning damage. If the target is a prone creature, it takes an additional 2d6 bludgeoning damage.

Bonus Actions

Disgorge Zombie. As a bonus action, the tyrannosaurus zombie can disgorge a normal zombie, which appears in an unoccupied space within 10 feet of it. The disgorged zombie acts on its own initiative count. After a zombie is disgorged, roll a d6. On a roll of 1, the tyrannosaurus zombie runs out of zombies to disgorge and loses this trait.