The Pokémon franchise was able to gain massive popularity right from its debut, but over time the series has reached even crazier levels of popularity that have turned it into one of the most successful properties of all time. Pokémon has evolved far beyond a video games series and it’s even become a celebrated a live-action film.
Each new generation in the mainline franchise introduces more Pokémon into the mix and even though Generation IV marked some important changes for the series, the Sinnoh Pokédex contains some controversial additions. Sinnoh has its share of memorable Pokémon, but there are also plenty that are completely forgettable when looking at the franchise as a whole.
10 Lickilicky
The Sinnoh region gets creative and adds a whole bunch of new evolutionary forms with pre-existing Pokémon and really embraces Baby Pokémon. Lickilicky doesn't follow that example, which makes its forgettable nature hurt even more. This is just a weirder, less effective version of a Lickitung that will come into existence if the Pokémon learns the move Rollout.
Lickilicky doesn't do enough differently and it's easy to miss. Lickilicky is kind of tragic since the Pokémon’s proficiency with its tongue leads to the rest of its body becoming useless. It's a cautionary tale more than it's an exciting new Pokémon.
9 Phione
There are plenty of reasons that Pokémon can be forgettable, but one of the more common is if that Pokémon is obtained through obscure means and wasn't commonly in people's parties. Phione is very easy to overlook and even then it’s comprised from similar traits of other guardian Pokémon.
Phione can only be acquired by breeding a Manapy (or another Phione) with a Ditto. It produces this mythical water Pokémon that doesn't make an impact, so it's only fitting it's made through a process of imitation.
8 Bonsly
Bonsly is another take on the Sinnoh region's addition of new Baby Pokémon. There is nothing wrong with Bonsly, but it's a Pokémon that suffers from the fact that its evolutionary form, Sudowoodo, is not only much more popular, but readily out in the wild. There are just a lot more common and powerful rock-type Pokémon in Sinnoh. In terms of Baby Pokémon, it's on the more irrelevant side, but it's a little more popular than others on here due to how Brock acquires one in the anime.
7 Spiritomb
Ghost-type Pokémon are one of the more exciting varieties of the creatures and it's led to some of the most unnerving Pokémon. Previous generations before Sinnoh did a good job with the ghost-types, but Spiritomb is more of a disturbing story than a Pokémon. It's an ethereal fog that is emitted from a powerful rock that comes into existence when 108 spirits are trapped in that rock. Spiritomb is a collection of evil spirits that want to get revenge on the world and it feels like it belongs in a Fatal Frame game more than it does in a Pokémon title.
6 Yanmega
By the time that the Pokémon series reached Generation IV and visited the Sinnoh region it had already hit a lot of the obvious bases for some of the more direct types of Pokémon, with bug-type Pokémon being a prime example. Yanmega is a dragonfly Pokémon that can create shockwaves with its wings, but it's not bringing anything new to the table. Its previous form, Yanma, is also forgettable, but they're more common in the area. However, it's a little more popular due to how Jessie gets one in the anime.
5 Mothim
The Pokémon series steadily incorporates new concepts and different ways to evolve Pokémon, some of which make a lot of sense and others become far too specific. Mothim leans more towards the latter. It's a bug- and flying-type Pokémon that will only evolve from a male Burmy that reaches level 20. This male form of the moth Pokémon feels more like a way to pad out the Pokédex and play around with the gender feature in the game. There are far better moth Pokémon out there and Mothim offers nothing new.
4 Finneon
At the end of the day, Finneon is just another fish Pokémon. There's nothing else going on here and it's very easy to forget this Pokémon exists because its generic fish design doesn't stand out in the least and its name feels like a rejected water-type evolution of Eevee. Perhaps if Finneon was actually powerful or offered something interesting with its moveset or backstory then it’d manage to make a strong impression, but it’s the opposite here. Finneon is just a water-type and nothing else, which doesn't even make it useful in battle.
3 Chingling
Some of the most powerful Pokémon from the franchise are psychic-types. These Pokémon possess frightening powers over the mind, Pokémon or otherwise. Chingling is easy to overlook for the fact that it’s a psychic-type Baby Pokémon that takes its inspiration from a bell (complete with weird tassel-like appendages). Chingling doesn’t bring much to the table and it feels more like a rushed idea for a Pokémon than something that was heavily developed. Even the Pokémon’s evolved form, Chimeco, is forgettable due to how it needs to evolve at night with a high friendship level, a strange set of circumstances.
2 Cherubi
Cherubi has a cute design, but grass-type is a crowded variety of Pokémon and there’s no need for bringing in more unless they’re actually doing something different. Cherubi is exactly the kind of expendable fodder that fills up random Routes. Cherubi evolves into Cherrim at level 25 and even that Pokémon is pretty lackluster with nothing exciting being incorporated into its new form. It makes Cherubi feel even more useless in the process. It's also one of the few Pokémon that has a natural predator in the form of the Starly, which means it could even become extinct some day.
1 Lumineon
Lumineon is not only as derivative as the Pokémon series gets, but it’s a Pokémon that’s actually a little insulting. There are many unique and exciting water-type Pokémon, but Finneon represents a generic fish and yet somehow its evolutionary form, Lumineon, is even worse. It takes on a design that is actually more forgettable and just feels like a real fish rather than a Pokémon. Lumineon is acquired by pushing Finneon all the way to level 31 and this feels like an empty reward. Lumineon still only a water-type, so this evolved Pokémon doesn’t even improve in that respect.