You raise a gargantuan undead creature to fight for you. Choose a corpse of a gargantuan or huge creature within range. The Challenge Rating (CR) of the creature used to create the Behemoth must be equal to or less than three-fourths of the caster’s level. The corpse is consumed, and in its place an Undead Behemoth is formed.

The Behemoth has the hit points of its original form, and it possesses all of their physical abilities and attacks. It acts on your initiative and follows your commands. The Behemoth cannot be controlled by any other creature. Its type changes to undead. It gains resistance to necrotic damage and immunity to poison damage and the poisoned condition. It also gains darkvision out to 60 feet if it didn’t have it already.

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 120 feet of you (if you control multiple creatures, you can command any or all 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 during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you issue no commands, the creature only defends itself against hostile creatures. Once given an order, the creature continues to follow it until its task is complete.

The Behemoth lasts until it drops to 0 hit points, at which point the creature used to create it is permanently destroyed.