It’s clear at this point that the Pokémon series isn’t in any danger of going away. Nintendo’s franchise has hit unprecedented levels of success where the games themselves are not only incredibly popular, but there are anime, feature films, and trading card games that also have huge audiences.
The versatility of the Pokémon series is what makes it so easy to enjoy and this is particularly prevalent in the different types of Pokémon that fill up the games. Fire-Type Pokémon have been around since the start and they contain some of the most popular creatures from the series, but there’s also a fair share of Fire Pokémon that seem like jokes and it’s easy to forget that they exist.
10 Magby
Generations II and III for Pokémon started to really experiment with the idea of Baby Pokémon and adding previous evolutionary forms to already established Pokémon. This practice works better for some Pokémon than others and while some of these new Pokémon are memorable and adorable, others just feel like filler. Magby isn't completely forgettable, but it's a Pokémon that greatly pales in comparison to both Magmar and even Magmortar. Considering that Magmar are already common enough on their own, it's not as if a Magby is ever an essential Pokémon. It's easy to overlook this piece in the evolutionary chain.
9 Heat Rotom
Rotom is one of the more unique Pokémon to come around and it's a good example of just how creative some of the ideas behind new Pokémon have become. Rotom is a Ghost-Type Pokémon that's able to possess the motors of certain appliances, so when Rotom invades a microwave oven, it becomes Heat Rotom and turns into an example of a Fire- and Electric-Type Pokémon. Rotom can be easy to forget and a lot of the time it's the appliances that it becomes that are more practical. Heat Rotom is a very different idea, but one that's easy to miss.
8 Numel
One of the most popular and earliest strategies for the development of new Pokémon designs involves taking normal animals and then giving them some creative elemental twist. Numel, for example, takes its inspiration from a camel, but its lackadaisical demeanor makes it an unessential Pokémon that's easy to get by without.
Generation III marks some growing pains with Pokémon designs and Numel fits that archetype. It's not the weakest of Fire-Type Pokémon, but even its evolved form, Camerupt, feels forgettable in the grander scheme of the series. Other Pokémon fulfill the same purpose, but better.
7 Litwick
Ghost-Type Pokémon feature some of the more unusual Pokémon designs, but later entries in the franchise have tried to do creative things with this sect of Pokémon. In the defense of Generation V's Litwick, the Fire- and Ghost-Type Pokémon has an adorable appearance, but it's not very useful. Litwick's look draws inspiration from a lit candle, which is simultaneously creepy and charming. The biggest factor with Litwick is that its subsequent evolutionary forms, Lampent and Chandelure, are much more memorable and better takes on the same idea. It's easy to forget that this first stage of the process exists.
6 Slugma
Some Pokémon suffer the unfortunate fate that they seem like they exist solely to be made fun of or act as reflections of how much more powerful other Pokémon are. Slugma is Pokémon that’s introduced in Generation II and it’s a perpetual downer on every level. Slugma emotionally resembles the Eeyore of the Pokémon world and it’s not going to be very helpful in battle either. Even Slugma’s evolved form, Magcargo, isn’t much of an improvement and it’s easy to forget that both of these Fire-Type Pokémon are out there in the world.
5 Heatran
Legendary Pokémon are typically some of the most memorable creatures, but the Pokémon games have gotten more generous in the department and suddenly the addition of one or two Legendary Pokémon in each new game has gotten much more cumbersome. Heatran, from Generation IV, is an example of one of these Pokemon that falls through the cracks.
Despite how a combination of Fire- and Steel-Types is uncommon, Heatran doesn't feel as epic as the other new Legendary Pokémon. The Pokémon is featured well in Arceus and the Jewel of Life, but it's been a long time since that film.
4 Oricorio (Baile Style)
It’s become expected for a new Pokémon title to try and come up with a fresh way to evolve Pokémon or do something clever with the franchise’s established rules. Generation VII turns the Flying-Type Pokémon, Oricorio, into its test subject. Oriocorio doesn’t evolve, but it will take on a different form depending on what variety of nectar from the several Alolan Islands it consumes. The Red Nectar will give Oricorio its Baile Style form, which makes it a Fire-Type along with Flying. It's a cute, playful Pokémon, but one that can get lost in the shuffle.
3 Larvesta
Much like in real life, the Bug-Type Pokémon get a lot of derision and it’s easy to pretend that the bulk of these Pokémon don’t exist. Granted, not every Bug-Type Pokémon is useless, but their constant appearances in forest areas can make them seem more like a nuisance than an incentive. Larvesta is at least a combination of Bug- and Fire-Types and it does evolve into a superior Pokémon, but it almost seems like an insulting exercise in masochism. Larvesta doesn’t evolve into Volcarona until Level 59 and it requires much patience.
2 Castform (Sunny Form)
Generation III experiments a lot with weather conditions and how this can make a difference for both when certain Pokémon can be obtained, but also how others will evolve. Castform is a very blank slate of a Normal-Type Pokémon, but it's able to become various different types depending on the current weather. Harsh sunlight leads to Castform's Sunny Form, which makes the Pokémon a Fire-Type. It's an interesting approach to get more value out of a Pokémon, but Castform is no Eevee.
1 Sizzlipede
Sizzlipede is another hybrid between Fire- and Bug-Type Pokémon, but since it’s a fairly recent introduction who has only come along in Pokémon Sword and Shield, it hasn’t been around long enough to gain the same reputation as other Fire-Type Pokémon. Sizzlipede feels very inconsequential and its design leaves even more to be desired. There's nothing at all memorable about this Pokémon and even its evolved form, Centiskorch, is another Fire-Type Pokémon that feels derivative of other better Pokémon. Generation VIII has some excellent new Fire-Type Pokémon, but Sizzlipede is not one of them.