Power Word Stun Spell
D&D Description of the Power Word Stun Spell : You utter a single word of power that instantly causes one creature of your choice to become stunned, whether the creature can hear the word or not. The duration of the spell depends on the target's current hit point total. Any creature that currently has 151 or more hit points is unaffected by power word stun.
Deeper info on this Dungeons & Dragons Power Word Stun Spell