Alpha Werebat

Shapechanger. The werebat can use its action to polymorph into a Large bat-humanoid hybrid or into a giant bat, or back into its true form, which is humanoid. Its statistics, other than its size and AC, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Echo Location. The werebat has advantage on wisdom (perception) checks that rely on hearing.

Speak with Bats. The werebat can communicate with bats and bat-like creatures as if they shared a language.

The Alpha Werebat can make 3 attacks one with its claws, one with its bite, and one with its wings or it can use its sonic screech.

Claw. Melee Weapon Attack: +8 to hit, reach  5 ft., 1 target. Hit:  19(3d8 + 5)slashing  damage. 

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., 1 target. Hit: 19 (3d8 + 5) piercing  damage and the Alpha Were Bat regains hit points equal to that amount half the amount of damage it dealt. 

Wing. Melee weapon Attack +8 to hit, reach 10 ft., 2 targets Hit  14 (2d8+5) bludgeoning damage and the target(s) must make a DC16 strength save. On a failure the target is knock prone. 

Sonic Screech (recharge 5-6). Everything within 60ft of Alpha Werebat must make a DC 17 wisdom save or take 6d8 thunder damage and if failed by 5 or more the target is stunned until the end of the Were Bat's next turn. On a success they take half.

Gale Push (recharge 6).  Everything in front of the werebat within 100ft must make a DC17 Strength save or be push back 30ft and knock prone. On a success the the target is only push back 10ft and isn't knock prone.