Fearow was a leader of a group of Spearow, which attacked and exhausted Ash's Pikachu. However, Pikachu defeated Fearow with a Thunder Shock, so Ash was able to catch it, turning Fearow into one of his most used Pokémon in this manga, staying with him the entire way. In Play Misty For Me, Ash attempts to have it battle against Misty at the Cerulean Gym (during which he had to get his hat back from her), but it comes out with a sign around its neck saying, "Sleeping. Do not disturb." Only when Ash threw its favorite food, a soy sauce-covered dumpling, at Misty did it actually do anything.
When Ash returned to Pallet Town in Pallet Party Panic, this Fearow was again causing trouble, this time for a flock of Pidgey and Pidgeotto. After his own Pidgeotto evolved into a Pidgeot, Ash attempted to capture the Fearow while riding on Pidgeot's back. Despite its weakened state, he was still unable to capture it, and left Pidgeot behind to guard against any future attacks.
Fearow led a flock of Spearow sometime prior to evolution after Ash threw a rock at it. The leader Spearow called out its flock to attack Ash and Pikachu. It continued to do so even after evolving as shown by its next appearance.
Spearow appears in I Choose You!. When Ash throws a rock at a Pidgey, it dodges it and the rock hit Spearow instead. It calls forth the whole flock and they attack Ash and Pikachu. They chase the two until Pikachu uses an Electric-type move to defeat the flock.
Spearow appears in Pocket Monsters the Movie: I Choose You! Remix. When Ash throws a Poké Ball at Pidgey, attempting to catch it, Pikachu blocks the Poké Ball with its tail and it hits Spearow's head instead. This causes the whole flock of Spearow to attack Ash and Pikachu. Pikachu is later able to defeat the flock with an Electric-type move.