Were Bat

Small humanoid (Goblin, Shapechanger), neutral evil
Armor Class 13
Hit Points 24 (7d6)
Speed 30 ft. (climb 30 ft., fly 60 ft. in bat or hybrid form)
STR
8 (-1)
DEX
17 (+3)
CON
10 (+0)
INT
10 (+0)
WIS
12 (+1)
CHA
8 (-1)
Skills Perception +3, Stealth +5
Damage Immunities bludgeoning, piercing, and slashing from nonmagical attacks not made with silvered weapons
Senses darkvision 60 ft., passive Perception 13
Languages Goblin (can't speak in bat form)
Challenge 2 (450 XP)
Shapechanger.
Echolocation (Bat or Hybrid Form Only).
Keen Hearing.
Nimble Escape (Humanoid Form Only).
Sunlight Sensitivity.
Actions
Multiattack (Humanoid or Hybrid Form Only).
Bite (Bat or Hybrid Form Only).
Scimitar (Humanoid or Hybrid Form Only).
Shortbow (Humanoid or Hybrid Form Only).

This full creature's stat block is not available (not OGL).

Most werebats are of goblin stock.
Adventures (Dungeon of the Mad Mage)