The Yellow Sign

You reveal an eldritch symbol seen only on the shores of Carcosa millennia ago. Any hostile creature within 50 ft of you immediately looks at the Sign and becomes completely focused on it, ignoring everything else. Each creature must succeed on an Wisdom saving throw or be considered Frightened for a number of rounds equal to your half your spellcasting class level (rounded down) and be afflicted with short term madness, as Hastur’s Sign violates their minds. The short term madness takes effect after the Frightened condition wears off.

Non-sentient creatures, i.e. beasts, plants, etc, are unaffected by this spell, however, DM fiat on what creatures are ultimately affected by the spell.