It's a Bad Bat. If you don't do
Bad Bats are creepy-looking bats that only appear in Majora's Mask. They are very similar to Keese, though there are a few differences, such as their large size in comparison to Keese. Also, Keese are usually found in dungeons and caves, while Bad Bats are typically found outside (except for in Stone Tower Temple and Beneath the Graveyard).