Doppelganger

The monster makes two attacks and uses if available.

(), reach . .

The monster casts Detect Thoughts, requiring no spell components and using Charisma as the spellcasting ability (spell save DC ).

Wisdom Saving Throw: DC , each in a -foot Emanation originating from the monster that can see the monster.
Failure: The target has the Frightened condition and repeats the save at the end of each of its turns, ending the effect on itself on a success. After , it succeeds automatically.

The monster shape-shifts into a , or it returns to its true form. Its game statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn't transformed.