Misty's Psyduck is shown as dimwitted and absent-minded. When it pops out of its Poké Ball, it really doesn't know how it got there. It is perpetually confused, and even when it summons powerful moves, it appears confused about how it pulled such a feat off. Its motivation for jumping out of its Poké Ball remains unknown, as it clearly does not enjoy or excel at battling. Even in the episode Just Add Water, it pushed Ash aside, wild with anger at Team Rocket's abduction of Misty (she had been captured while saving him) and insisting on battling. However, after a few seconds, it completely forgot what it was doing and went back to looking confused.
When other Pokémon attempt to hit on his head such as Ash's Kingler, Team Rocket's Meowth, Jessie's Arbok and the thieves' Poochyena, Psyduck becomes overprotective to its own head, knowing the attacks will give it a severe headache when attacked and its powerful moves such as Confusion and Psychic are about to be unleashed.
Psyduck also loves Misty despite its faults, it always tries to be there for her, whether she likes it or not. Misty constantly complains about Psyduck's faults and how its dopey look gives her a headache, but many suspect that she actually deeply cares for Psyduck though it has been suggested several times; she instantly shoots down such ideas, such as when Koga and Aya both offered a trade with her. Her antagonistic relationship with it is often compared to her relationship with Ash. It could also be compared with Jessie's relationship with her Wobbuffet. James once stated that Wobbuffet made Psyduck look good in comparison.
For comic purposes, Misty seems to go to the limit of violence with Psyduck, such as when she suggested she smash a bike on Psyduck's head in order to activate its psychic powers. Psyduck is quite unconcerned to these threats of violence, perhaps because it knows how Misty truly feels.
Although it can sometimes annoy Misty, she and Psyduck have a good bond, seeing how Misty refused to trade it for any Pokémon no matter what. Psyduck also can be quite useless at times because of it's oblivious nature and random headaches. Though it rarely fights, it has shown to be able to handle it's own when it gets serious.
In Hypno's Naptime, Misty accidentally dropped her Poké Ball and Psyduck, being curious, touched the Poké Ball, and got caught. During the journey, Psyduck often releases itself from its Poké Ball out of the blue, which would cause Misty to return it to its ball in annoyance.
In Pokémon Fashion Flash, Misty, upon being given the idea by a sarcastic Ash, decides to take Psyduck to the recently opened Salon Roquet to see if a makeover there would help him out. However, when Psyduck discovers that the stylists are really Jessie and James of Team Rocket, he shows some loyalty and concern for Misty's safety by running back to Suzy's salon and warning Pikachu, Ash, and Brock that Misty was in danger, so despite his normally dumb expression he has on most of the time, he does care for his Trainer and wants to help her when she's in trouble.
In The Ninja Poké Showdown, Misty tries to use her Starmie to fend off Team Rocket, but Psyduck automatically comes out to confront the group, much to her annoyance. As Jessie's Arbok manages to bite Psyduck's head, that caused it to have a headache. When they confronted the group again, Misty realizes Psyduck's abilities are about to be unleashed when it got a severe headache and it learns Disable to control the Team Rocket's Pokémon to knock the trio down before being blasted off by it from its newly learned Confusion to make Koga and Ash resume their Gym battle after the incident. Before the resumed gym battle, both Koga and Aya offer a trade to Misty for her Psyduck due to its Psychic-type abilities, but she disagrees due to her hate of Bug-type Pokémon when they offer both Aya's Venonat and Koga's Venomoth for Psyduck.
In The Breeding Center Secret, the characters are unsure of a Pokémon breeding center, and Misty suggests they leave Psyduck there and find out. She later admits that she cares for him, and says its cruel that they just used tape to straiten Psyduck's eyes.
In Princess vs Princess, Misty fights in the final round against Jessie. Most of her Pokemon such as Brock's Vulpix, Ash's Bulbasaur and Pikachu are defeated by Jessie's Lickitung and its Lick ability. When she attempts to use Staryu, Psyduck automatically pops out to fight, much to her frustration, she even tries to tell it to use its Water Gun, but to no avail due to being confused. When Lickitung tries its best to lick Psyduck, it has no effect until it attempts to lick it's head which Psyduck tries to avoid. Once Lickitung licks Psyduck's head, it caused Psyduck to have a headache, making Misty have it use it's Confusion to knock Lickitung towards Jessie and her group and send them blasting off the building's roof. Misty became victorious to win the doll collections in the Princess Festival and be crowned Queen of the Princess Festival.
In So Near, Yet So Far'Fetched, a kid doesn't want his Far'fetched to battle because he doesn't want it to get hurt. Misty offers to battle him and, you guessed it, Psyduck pops out! The Pokémon hits Psyduck's head with it's leek and Psyduck gets an ultimate migraine! His psychic powers make Far'fetched fly into a tree! Misty says, "You did it, Psyduck!" Psyduck blushes, psys, and makes a peace sign.
In Who gets to Keep Togepi?Ash and Misty battle for The Togepi and Ash calls on Bulbasaur. Unfortunately for Misty, Psyduck pops out! Misty tells Bulbasaur to aim for Psyduck's head and Ash says he's not *that* dense. He tells Bulbasaur to lick Psyduck on the head! Psyduck laughs because it tickles, but then Ash tells Bulbasaur to use Tickle Attack! The Vines tickled Psyduck's stomach so much, he couldn't attack. Misty returns him to his Poké Ball, her head down with her fist on the ground, moaning "no, no, no!"
In The Misty Mermaid!, Psyduck is revealed to be aquaphobic, which Misty's sisters are dismayed at when it was released to save Misty, but they remark Psyduck as pathetic. Psyduck is also rejected by them when they allow Starmie and Horsea to stay at the pool of Cerulean Gym.
In Lights, Camera Quack-tion!, Pikachu, Meowth, Arbok, Weezing, Vulpix and Psyduck enter an audition for a movie called Pokémon in Love, staring a prima Donna Wigglytuff and somebody else. After Arbok and Weezing are disqualified, and Wigglytuff starts slapping Pokémon, everyone leaves except for Psyduck! He is chosen for the role! Psyduck ends up saving Wigglytuff from Jessie and James and the two spend a moonlit night together. This relationship is never again looked at though.
In "Bye Bye Psyduck", Marina pointed out that Psyduck was close to evolving after seeing its glowing tail. Misty thought Psyduck had evolved into a Golduck after it's Poké Ball had fallen in the water and a Golduck resurfaced straight afterwards, but it was later revealed to be a wild Golduck.
In "The Stun Spore Detour", Misty uses Psyduck to fight off Team Rocket's Meowth, who manages to bite Psyduck's head, causing Psyduck to unleashes its headache-induced Confusion to knock it down along with James.
In The Fire-ing Squad!, Ash takes some of Misty's water Pokémon for his competing team. Psyduck is one of them. In a relay to put out a burning doghouse, Psyduck actually ends up in the burning building! Squirtle rescues him, luckily.
In The Perfect Match!, Psyduck released itself from its Poké Ball during the Whirl Cup tournament, forcing Misty to use it. Psyduck was pitted against a Kingler. Kingler used Vice Grip, clutching onto Psyduck's head, which caused it get a headache, but gave it that push to finish Kingler off with Confusion.
In Just Add Water, Psyduck later shows its aquaphobic behavior again when Misty releases it and it was seen hanging with a life saver. When Team Rocket captured Misty and her battler Dorian, this angered Psyduck, and it was determined to rescue Misty. During its battle with Jessie's Arbok, after it bites Psyduck's head to cause a headache, it unleashes Confusion to knock Arbok down towards Jessie, James, and Meowth, and learns Psychic. Using its new learned move, Psyduck blasts Team Rocket off into the sky.
In Cerulean Blues, Psyduck and Politoed were released by Misty to restrain her Gyarados at the Cerulean Gym, but failed due to Psyduck still being aquaphobic, and was blown away from Gyarados' rampage while Politoed claped happily when Misty got washed up from Gyarados' Hydro Pump until it obeys her when she saved her Corsola from Tentacruel's Poison Sting.
In The Blue Badge of Courage, Psyduck was trained to swim properly by Tracey when he visits Misty at the Cerulean Gym, but failed due to still being aquaphobic. Psyduck is also the main reason Misty fails, despite her best efforts with Tracey and Sakura to make their own Cascade Badges, who are trained by Kinso. When Kinso was robbed by thieves, Psyduck is used to fight the thieves' Poochyena and Zigzagoon while teaming up with Sakura's Espeon. Poochyena manages to bite Psyduck's head, causing it to have a headache while unleashing its abilities. Psyduck uses Disable to counterattack on Zigzagoon and bashes the thieves and their Pokemon into a tree with Confusion. After the incident, Kinso was pleased that Misty and her Psyduck proved her worth and decides to give them the badges.
In Luvdisc is a Many Splendored Thing, This is Psyduck's last and final appearance and it shows its aquaphobic yet again when both Misty and Daisy's Luvdisc are making rehersals for the mermaid and the prince theater play to pose them as they kiss each other.
After Luvdisc is a Many Splendored Thing, it was never seen again even when Misty traveled to Hoenn to meet up with Ash, Brock, May and Max in The Princess and the Togepi. It wasn't seen in the cameos Misty made when watching the conference and when Misty reunited with Ash at Pallet Town during the Pokémon: Advanced Generation series.
In its recent appearance, it was in the renewed Cerulean Gym, helping her to guard the Gym. It then battled with Lana's Popplio and Mallow's Steenee, but after it fell onto the ground when Steenee bursted Popplio's water balloon, it used Confusion on them until Misty told it to stop, though it suddenly started crying due to its headache.
|Disable||The Ninja Poké-Showdown|
|Scratch||The Ninja Poké-Showdown|
|Tail Whip||The Ninja Poké-Showdown|
|Confusion +||The Ninja Poké-Showdown|
|Water Gun +||The Battling Eevee Brothers|
|Psychic (move)||Just Add Water|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- Ironically, despite being a Water-type, Psyduck seems to be somewhat hydrophobic and can't swim. It's willing to go into water if it's wearing some kind of flotation device.
- Like all the Trainer's Pokemon in Mewtwo Strikes Back, Psyduck was cloned. However, unlike the other clones in the movies, Psyduck's clone was exactly like it and was just as dimwitted, if not more so.
- Unlike in the original series, Psyduck seems to have better ability to listen and understand Misty's instructions, control its Psychic powers better and the power of its Water Gun has boosted in the Sun and Moon series.