False-Hearted

Your feeble and scrawny physique leads others to overlook you:

• You gain proficiency in Charisma (Deception) checks.
• Enemies that attack you with weapon or spell attacks roll with disadvantage against you on the first round of combat.
• The first enemy you hit with a weapon or spell attack roll in the first round of combat must make a Wisdom saving throw equal to 8 + your proficiency bonus - your Constitution modifier or be surprised (unless they have the Alert feat).
• Your constitution cannot be raised above 9.
• You can choose to decrease your constitution by 1 after taking this feat.