Brock captured a Zubat when he spotted it on his way inside the cave but its capture was not seen on screen. He later sent out Zubat to battle Team Rocket. He rarely used Zubat for direct combat, instead focusing on confusing opponents with Supersonic.
In Johto Brock encountered a doctor who had a female Zubat. Brock used his Zubat to in a fight against Team Rocket. While battling, Zubat evolved into a Golbat. Brock's Golbat was only a Golbat for a short period of time. He soon evolved into a Crobat in a battle with Team Rocket.
He is male because in episode 165 "Hassle in the Castle" Brock used him to impress a trainer who had a female Zubat.
In both the Japanese and English versions of the anime, he is voiced by Shin-ichiro Miki who is best known for playing James of Team Rocket in the original Japanese version and who also plays Misty's Staryu and Ash's Charizard.