Werebat

A character who becomes a lycanthrope retains his or her statistics except as specified by lycanthrope type. The character gains the lycanthrope’s speeds in nonhumanoid form, damage immunities, traits, and actions that don’t involve equipment. The character is proficient with the lycanthrope’s natural attacks, such as its bite or claws, which deal damage as shown in the lycanthrope’s statistics. The character can’t speak while in animal form.

A non-lycanthrope humanoid hit by an attack that carries the curse of lycanthropy must succeed on a Constitution saving throw (DC 8 + the lycanthrope’s proficiency bonus + the lycanthrope’s Constitution modifier) or be cursed. If the character embraces the curse, his or her alignment becomes the one defined for the lycanthrope. The DM is free to decide that a change in alignment places the character under DM control until the curse of lycanthropy is removed.

The following information applies to this specific lycanthrope.

Werebat. A character that becomes a werebat gains a Dexterity of 16 if his or her score isn't already higher, and a +1 bonus to AC while in bat or hybrid form (from natural armour). Attack and damage rolls for the bite are based on whichever is higher of the character’s Strength and Dexterity. You gain the following abilities:

• Echolocation. The bat can't use its Blindsight while Deafened.
• Keen Hearing. The bat has advantage on Wisdom (Perception) checks that rely on hearing.
• Bite. 1d6 + Dex/Str piercing damage
• Claws. 1d6 + Dex/Str Slashing damage
• Swoop. The werebat can only use this attack if it begins its turn in flight. The werebat flies low over a target, slashing it with its hind claws before flying away. The werebat uses up to its full movement towards a target, makes one claw attack with advantage on the attack roll or one grapple check with advantage on the roll, then uses the Dash action as a bonus action to fly away. Any opportunity attacks made against the werebat when it uses this action are made with disadvantage.