Crobat debuted in Clefairy and the Moon Stone as a Zubat flying out of Mt. Moon with many others of its kind. Unlike most captures, this was never shown happening, and it did not become known that Brock had captured one until he used it in a battle against Ekans and Koffing. Ash was puzzled by its appearance, and Brock explained that he had caught it before they entered the cave, much to Ash's frustration as he realized that he should have caught one as well. Zubat used Whirlwind alongside Ash's Butterfree to repel a Smokescreen, but it was tackled by Koffing. It recovered and used Supersonic, causing Ekans and Koffing to turn on each other and allowing Butterfree to send them flying.
In Hassle in the Castle, Ash, Misty, and Brock entered a castle where a woman named Dr. Anna used different Pokémon for diagnosing and treating patients. One of these was her Zubat, Mimi, which used its Supersonic move to scan patients. Eager to impress the doctor, Brock sent out his Zubat to assist her. Jessie, James, and Meowth entered the scene, and as Dr. Anna, Brock, and the two Zubat pursued them, causing them to become stuck in an underground maze. Dr. Anna had Mimi use Supersonic again to create a map, and with the assistance of Brock's Zubat an entire map of the maze was generated. They wandered through the maze and encountered multiple traps until their Zubat were able to find the exit door. It wouldn't open, however, and Team Rocket were given the opportunity to grab both of the Zubat, only to find themselves stuck as well. They were eventually freed from the maze by Pineco's Self-Destruct and the two Zubat flew free of the bag they were held in. Team Rocket tried to make off with Ash's Pikachu, but the two Zubat blew away Weezing's Smokescreen and Brock's Zubat engaged in battle with Team Rocket's Pokémon. During this battle, it evolved into Golbat, and was able to send Team Rocket packing with the help of Pikachu. Brock had hoped to stay and help Dr. Anna, but had his hopes crushed when he learned that Golbat was so strong that its Supersonic overloaded Dr. Anna's computer.
Golbat and Pineco watched over Brock when he fell ill in Sick Daze. It used Supersonic to prevent him overexerting himself and keep him in bed. It also helped rescue all of the stolen Pokémon by destroying the balloon with Wing Attack, and attacking Arbok and Weezing, again with Pineco.
In Control Freak!, Brock found and agreed to help a woman who was looking for two artifacts which were supposedly buried nearby and had been used by a queen to control Pokémon. Possibly having learned to do such from his encounter with Dr. Anna, Brock was able to hook up Golbat to her computer and display a map of the underground. They reached the chamber only to find Team Rocket had beaten them there and Jessie was using the artifacts to control Pokémon. Brock's Golbat was the only Pokémon that could resist the effects of the artifacts, and countered it using its Supersonic. Jessie turned Brock's Geodude and Onix against him, and it was trapped under the rubble of Onix's Dig. Brock was able to locate Golbat under the rocks by listening carefully for the sound waves, somehow having ears sensitive enough to pick up the ultrasonic waves. They tracked down Team Rocket to find them leaving, appropriately, in a rocket. Golbat and Ash's Noctowl flew after the rocket, but could not keep up. Brock called out to Golbat, and this caused it to evolve into Crobat. It easily overtook Noctowl and the rocket and destroyed it with a Wing Attack.
Crobat only appeared as Brock was lending it, along with his Onix and Geodude, to his younger brother Forrest. It also made a brief appearance in Grating Spaces, where it welcomed Brock home along with the rest of his Pokémon.
Despite its few appearances, Crobat was shown to be very loyal towards its Trainer, due to the amount of training it received and the care Brock gave it. Its impeccable speed and Supersonic sonar proved to be useful on many occasions, like finding missing Pokémon or guiding Brock and his friends through otherwise treacherous caverns.
Brock's Crobat was featured in the TCG multiple times. The following is a list of cards named Brock's Zubat, Brock's Golbat or Brock's Crobat.
Brock's Zubat Cards listed with a blue background are only legal to use in the current Expanded format. Cards listed with a silver background are legal to use in both the current Standard and Expanded formats.