Animate Dead Monster

Choose a corpse of a Monster within range. The target becomes an Undead creature. only creatures that left corpses made of flesh and bones can be targeted by this spell.

you can make the folowing changes to the creature's statblock to make a zombified version of it:

Creature type: undead

Alignment: neutral evil

AC: reduce by 3

HP: increase by 22

speed: reduce walking speed by 10ft. if the creature had another type of speed like flying speed, reduce it by 10ft too.

new ability scores: str: don't change/ dex: 8/ const: 16/ int: 3/ wis: 6/ char: 5

Imunities: in adition to the resistences and imunities it had, the creature gains proficiency to poison damage and the condition poisoned. It loses any other imunity or resistences related to mental, magical or abilities. consult your GM.

Senses: change passive perception to 8. Now, the creature has darkvision 60ft. If the creature finds its way by other means, consult your GM.

Language: the creature can understand any language it knew in life, but can't speak.

traits: The creature loses all features it had.

the creature gains the feature "Undead fortitude: If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 +the damage taken, un less the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point in stead."

attacks: the creature keeps all the fisical atacks that doesn't require dexterity or mental ability. the only weapons they are capable of using are clubs, hammers and maces. also, attacks that are signature moves of the creature, could be kept, but in a weaker version, like the ray powers of the zombie beholder from the 5e monster manual. Use your creativity and consult your GM, he or she has the final word on the matter.

the creature will lose all their legendary actions, lair actions and legendary resistences it had.

On each of your turns, you can take a Bonus Action to mentally command any creature you made with this spell if the creature is within 60 feet of you (if you control multiple creatures, you can command any of them at the same time, issuing the same command to each one). You decide what action the creature will take and where it will move on its next turn, or you can issue a general command, such as to guard a chamber or corridor. If you issue no commands, the creature takes the Dodge action and moves only to avoid harm. Once given an order, the creature continues to follow it until its task is complete.

The creature is under your control for 24 hours, after which it stops obeying any command you’ve given it and becomes savage. To maintain control of the creature for another 24 hours, you must cast this spell on the creature again before the current 24-hour period ends.

Using a Higher-Level Spell Slot. You create or reassert control over one additional Undead creatures for each spell slot level above 5. Each of the creatures must come from a different corpse.