(This material is is from "Starter Spells" from Unearthed Arcana (Link:http://dnd.wizards.com/articles-tags/unearthed-arcana) This content is not official but is avaible for playtesting)
Casting Time: 1 action
Range: 60 feet
Components: V, S
Duration: Concentration, up to one minute
You awaken the sense of mortality in one creature you can see within range. The target must succeed on a Wisdom saving throw or become frightened for the duration. A target with 25 hit points or fewer makes the saving throw with disadvantage. The spell has no effect on constructs or undead.