The Pokémon series has only gotten bigger since its debut and it’s been amazing to see the ways in which it’s been able to expand its universe. The Pokémon anime has been as popular for nearly as long as the video game series and in some ways it’s been able to engage with an entirely different audience who aren’t necessarily gamers.
Part of what has helped the Pokémon anime remain so successful is that its protagonist, Ash Ketchum, remains an anchor throughout it all. Ash has shown his worth as a Pokémon trainer in many ways and captured some impressive Pokémon, but there are also plenty that it feels like he’s completely abandoned.
10 Muk Gets Immediately Abandoned
Muk can be an intimidating Pokémon within the right context and even when Ash first encounters the Pokémon in his earlier adventures it's something that gives him a lot of pause. Unfortunately, Muk is treated more like an inconvenience to Ash than a viable partner in battle.
The minute that Ash captures Muk he sends it off to Professor Oak's laboratory because it's rancid stench is so intense that it can get through its Poké Ball. Muk has reappeared several times, but usually in a comedic capacity and it's unlikely that the Pokémon will ever leave Professor Oak's care.
9 Heracross Is Ash’s First Johto Pokémon
Heracross is a formidable Bug-Type Pokémon who's significant in the sense that it's the first Pokémon that Ash catches during his time in the Johto region. Heracross is a faithful companion to Ash during his time in Johto, but considering the Pokémon's connection to Ash it's surprising to see him get left behind like so many others.
Ash leaves Heracross with Professor Oak so that he can better study his species. Later on, Heracross is supposed to return to Ash, but Cyndaquil gets sent instead. Ash occasionally reunites with the Pokémon, but their bond should still be greater.
8 Snorlax Requires Too Much Food And Maintenance
Snorlax is an important Pokémon in both the video games and anime and Ash manages to catch one during his time in the Orange Islands with the help of Jigglypuff and Pikachu. Ash makes decent use of Snorlax during his Orange Islands escapades, but he turns on him during the Orange League and it leads to Ash ditching Snorlax with Professor Oak.
He decides that the Pokémon requires too much food and that he can’t do him justice. Ash is so negligent towards his Snorlax that when he encounters another in Pokémon Journeys he confuses it for a Daimax.
7 Rowlet Is Ash’s Introduction To Alola
Rowlet is actually one of Ash's more recent Pokémon, but also one that speaks to the trainer's nature to often wipe his Pokémon slate clean when he moves forward to a new region. Howlet is an adorable owl-like Pokémon that's Ash's first capture in the Alolan region.
Ash often allows Howlet to follow him outside of its Poké Ball, but it’s still a Pokémon that Ash leaves in the care of Professors Kukui and Burnet after he exits Alola. Rowlet reappears once in Pokémon Journeys, but it feels like an afterthought for a Pokémon that was so important to Ash.
6 Ash Has Multiple Tauros And Forgets Them All
Tauros is a decent Normal-Type Pokémon from the first generation of games and any early trainer that’s in Ash’s position at this point in the anime series would be ecstatic to capture such a Pokémon. However, the circumstances behind Ash’s many Tauros is unusual and he ends up unintentionally collecting a whole herd during his time at the Safari Zone.
Ash does eventually use Tauros on a few occasions during some of his Pokémon League battles, but for the most part Ash views them as a mistake that’s kept over at Professor Oak’s laboratory for safekeeping.
5 Swellow Is Ash’s Hoenn Helper
Ash has had many different bird Pokémon throughout anime, but Swellow is a special member of his team since its the first Pokémon that he catches within the Hoenn region. Ash actually catches the Pokémon when it's still a Taillow and he helps it evolve into the Swellow. Swellow is an important member of Ash's team during his Hoenn escapades and it helps him win some important matches.
Swellow makes a welcome appearance briefly in the Diamond and Pearl anime during Ash's semifinal battle, but other than this the Pokémon has been left behind with Professor Oak for newer creatures.
4 Donphan Gets Raised From An Egg
Some of the Pokémon that Ash encounters are already self sufficient upon capture, but when it comes to Ash's Donphan he raises it all of the way from a Phanpy Egg. Ash goes on quite the journey through Johto as he helps the egg hatch and Phanpy evolve into Donphan.
Donphan is repeatedly useful to Ash and helps him win many battles, but he's yet another Pokémon that Ash leaves behind with Professor Oak once he decides to embark for the Sinnoh region. Donphan doesn't get addressed nearly as often as it should considering everything its seen with Ash.
3 Buizel Is One Of Ash’s Most Important Pokémon Trades
Buizel is a quirky Pokémon that loves to fight and is a useful ally for Ash during his Sinnoh tournament battles. What's interesting about Buizel is that it's actually Ash's friend, Dawn, who captures the Pokémon. Ash and Dawn trade Pokémon after they realize that they're better suited for each other and Ash loses his Aipom in the process.
Buizel gets lots of love in Sinnoh, but doesn't get much attention after that. When Ash leaves for Unova he shackles Professor Oak with Buizel, which seems a little callous considering the work that Dawn has also put into the Pokémon.
2 Torkoal Is Ash’s Emotional Fire-Type
Fire-Type Pokémon are easily one of the more popular varieties and Ash has had many powerful types within his party. Torkoal joins up with Ash during his Hoenn explorations and he forms a close bond with the Pokémon. Torkoal is highly emotional and often cries and turns to Ash for comfort.
That being said, it's also a deceptively powerful Pokémon that's helped Ash out of many situations. Due to Torkoal's fragility, it seems like this should be a Pokémon that Ash keeps close, but he instead leaves it with Professor Oak so it can connect with his Cyndaquil.
1 Snivy Considers Ash A Worthy Trainer
Snivy is one of the more mysterious Pokémon that Ash comes to possess. Snivy shows tons of skill for a wild Pokémon and it's speculated that she had a previous trainer that she abandoned because she didn't deem them worthy.
This makes Snivy's bond with Ash all the more important because she does seem to find acceptance through him. Ash gets lots of use out of Snivy during his time in Unova, but the Pokémon hasn't remained a part of Ash's party. Snivy makes real progress while by Ash's side and it's sad to think how she may be doing while just left in a lab.