These enemies are some of the most generic enemies in the Seiken Densetsu series. While other monsters will have some mystical or strange embellishment the Bats in the series are pretty much just Bats. They generally attack with bites and modified echolocation.
Bats did not direcly appear as enemies, but they could be summoned to hurt you by the Vampire.
In SoM Bats are classified as Animals.
Blat / Batra (J)
Blats live in the Haunted Forest and the caves at Gaia’s Navel. They fly around and attack with bites. They can cast Balloon on you.
Grave Bat / Dark Bat (J)
These enemies are summoned by Fierce Heads in the Palace of Darkness. They can cast HP absorb.
In SD3 Bats are classified as a Animals.
These batty enemies frequent the Molebear Highlands, Cave of Waterfalls, Dwarf Cave and the Golden Road at night. They attack with bites and have a Sonic Wave which can cause a Mind Down status. Their eyes can be used to inflict Mind Down on an enemy.
These Dark Battums are only found in the Moonlight Forest. They have the same bite attack as normal Battums, but instead of a Sonic Wave they can use Mind Drain to decrease a characters Mind Status. The attack has a high failure rate.
In LoM Bats are classified as Aerial.
Blood Sucker / Battma (J)
Bloodsuckers are found in caves and other dark areas throughout Fa’Diel. They attack with bites, rams and super-sonic waves. As a pet they will defend you against becoming confused.