Bat

The bat is a Hashtag Dungeon monster and its noticeable qualities are that is occasionally has a burst of speed, it is supposed that it is the bat flapping it wings. It follows the player around the room and is completely hostile. As of Alpha 1.3, it can also travel through Rock.

Tactics
The bat often comes at high speeds, and as a result can't turn perfectly, keep moving and it shouldn't be able to hit you. Bats perform best group with other high speed enemies, in this case prioritise other targets as the bat is the likely the weakest of the enemies you may be facing.

Trivia

 * The bat is a low-level creature in Hashtag Dungeon, meaning it can be used to fill up the 'Difficulty' bar, fill empty spaces in a room, or as an abundance creature, to swarm the player to quickly kill the player.
 * The bat was likely one of the first creatures in Hashtag Dungeon, as in any version of the game, the bat was always the first on the 'Monster' list