Spider Bats worked for Revolta.
They are spider/bat hybrids, spiders with bat wings.
They were rude, dangerous, and sneaky.
Powers and abilites
They flew and could create hypnotic earmuffs.
Scooby-Doo and the Ghoul School
When Revolta raised her arm up after seeing the monsters coming to Miss Grimwood's school to see their daughters, a spider bat almost bit Revolta on the hand and she became angry as she slapped it. Revolta sent one of her Spider Bats to go after Shaggy Rogers. The Spider Bat reached Grimwood's school and hypnotized Shaggy with hypnotic earmuffs while he was asleep.
The next day Shaggy took the girls on a field trip to the Barren Bog (as Revolta had commanded him). Grim Creeper was in the swamp to lure the Grimwood Girls into the hut where the Spider Bats would mind-control them. They captured the girls and took them to Castle Revolta. Scooby-Doo was chased by Grim Creeper, but Matches the dragon saved him by burning Creeper with a blast of fire. The Spider Bats went to try and put two Grimwood girls back under Revolta's spell, but the Calloway cadets appeared and they dropped water balloons on the Spider Bats and killed them.
Revolta turned Scooby into a toad and told the Grimwood Girls to go back or Revolta will turn the rest into something worst than toads. A Spider Bat spied Scooby-Doo the toad and went after him to eat him. Scooby the toad and the Spider Bat knocked some wrong ingredients in the formula and it caused one of the girls to turn back to normal. Matches burned the Spider Bat and the later accidentally crashed into the helmets connected to the formula tubes. The formula went unstable and exploded; leaving an uncertain fate for Revolta, the Spider Bat, and her other minions.