Animate Memory

This spell targets the dead body of any medium or large creature within range, and causes it to re-shape into an animated copy of a monster of challenge rating 6 or lower that you have watched die.  The monster comes to life with the same game statistics and appearance it had in life, except it's hit point maximum is automatically set to double your spellcasting ability score, and its AC equals 8 + your proficiency bonus + your spellcasting ability modifier.  The actions it can take are restricted only to each attack present in its stat block, and it can only make one attack per turn. 

On each of your turns, you can use a bonus action to mentally command any creature you made with this spell if the creature is within 60 feet of you. You decide what action the creature will take and where it will move during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you give no commands, the creature defends itself but takes no other actions and does not move. Once you give an order, the creature will follow it until its task is complete.

The creature is under your control for 16 hours, after which it stops obeying any command you've given it. To maintain control of the creature for another 16 hours, you must cast this spell on the creature again before the current 16-hour period ends. If you use this spell to gain control of a new creature, then the previous one vanishes, returning to the corpse that was used in the original casting of the spell.