Blue obtained Golduck as a Psyduck and evolved him sometime prior to A Tale of Ninetales. He first appeared in A Tale of Ninetales, when Golduck is accidentally traded to Red alongside Blue's other Pokémon. During the three days that Red has them he attempts to get them to relax and open up to him, with little success. They later traded back, while keeping the caring attitude that Red installed in them.
In Peace of Mime, Golduck teams up with Pika in order to break into Saffron City. Pika uses his Substitute to get past the barrier and Golduck uses Confusion to pass the information back to their Trainers. Inside the city Pika runs into the one who created the barrier, a Mr. Mime. Despite Mr. Mime's evasive attempts, a coordinated Thunderbolt from Pika successfully faints the Barrier Pokémon, lifting the barrier.
In a flashback shown in Growing Out of Gengar, Golduck helped Blue in his battle against Agatha, where he channeled Blue's thoughts to his Pokédex to communicate with Evan while he was trapped in a Dream Eater and had to distract her Gengar.
In Weezing Winks Out, Golduck fought against Agatha, using his Confusion attack to defeat her and her Arbok. In Striking Golduck, Golduck was called out to fight Agatha's Gengar, but is quickly defeated after it attacks from the shadows.
In Red and Blue Make Purple Opponents, Golduck is used alongside Porygon2 in a double battle against Red and his Snor and Gyara. Gyara starts the battle off with his Ability Intimidate, and Blue responds by having Golduck use Iron Tail and Porygon2 use Tri Attack on Red's Pokémon. Red then has Gyara counter attack with Body Slam on Porygon2, while Snor attacks Golduck with Strength. Gyara next uses Hyper Beam on Golduck, and Golduck uses Dig to hide and avoid further damage. Red counters by having Snor use Earthquake, dealing damage to Porygon2, twice the damage to Golduck due to him being underground, which causes him to faint, and Gyara being unaffected due to him being part Flying-type.
In Storming the Forretress, after Giovanni was defeated and Carr sent the airship containing him, his son, his loyal subordinates, and enemies crashing, Golduck and Blasty used Hydro Pump to try to keep the airship in place with Rhydon using Megahorn. However, ultimately, it was Mew who saved it from crashing.
In The Final Battle VII, Golduck appeared alongside the rest of Blue's team when he was checking to make sure they all survived the petrification caused by Mewtwo and Darkrai.
Like most of Blue's Pokémon, Golduck is serious, calm, and focused. He is very loyal to his Trainer and gives everything he has in battle. However, he is usually used as support in battle to help his team gain the advantage, and he rarely takes a huge offensive approach. He is often used by Blue for his Psychic powers, which are utilized by the Pokédex.