As the original games celebrate their 20th anniversary, an aspiring Pokémon trainer now has an incredible 722 creatures to capture in order to complete their Pokédex. With the recent reveal of Pokémon Sun and Moon, there are sure to be a whole host of new Pokémon appearing on our 3DS consoles very soon, bringing that total up even higher.

Designing so many different creatures is by no means an easy task, but Nintendo have employed a great deal of creativity in their work. Now, as we wait for the reveal of the 7th generation creatures, it's time to look back over some of the more unique monsters throughout the history of Pokémon.

9 Arceus

Pokemon Arceus

Starting strong with the God of all Pokémon, Arceus is said to have created Sinnoh, Ransei, and quite possibly the rest of the Pokémon universe. According to the sometimes less than reliable Pokédex, Arceus was born from an egg in a place where there was nothing before creating the world. It is thought that Arceus was also the creator of other mythical Pokémon, namely the Lake Guardians: Uxie, Azelf, and Mesprit, as well as the Creation Trio: Dialga, Palkia and Giratina.

Arceus has an ability named Multitype which allows the creature to change it's type, based off the type of elemental plate it holds. It's signature move, Judgement, will also change type this way, allowing trainers worthy of capturing the Pokémon to adapt their strategy outside of battle.

8 Eevee

Pokemon Eevee

One of the most recognizable and beloved Pokémon, Eevee was the creature that Professor Oak originally planned to give the player in Pokémon Yellow before your rival claims it. It is also the player's starter Pokémon in the games Pokémon XD: Gale of Darkness and Pokémon Conquest.

While Eevee itself is not particularly interesting, its evolutions are what give the creature its place on the Top 10 list. As of generation 6, Eevee can evolve into any one of 8 different Pokémon of various types, allowing players to create a diverse team for battles. In earlier games, Eevee were incredibly rare, with the player being given only one. This meant that Pokémon fans were forced to choose carefully when it came to evolving their furry friend.

7 Shuckle

Pokemon Shuckle

A hidden gem, Shuckle's unique fighting style is something that many players will never even know to fear. This unassuming turtle-like creature boasts the highest base Special Defense and Defense stats in the game, tying for the latter with Mega Aggron and Mega Steelix. What's more, Shuckle learns a move named Power Trick, allowing the creature to swap its incredibly high Defense with it's low Attack stat and temporarily becoming the Pokémon with the highest Attack in any of the currently released games.

While a level 100 Shuckle could potentially deliver the most powerful hit in the game, the Pokémon suffers from the lowest Speed and Special Attack stats. Despite this, Shuckle has a special ability that makes it an invaluable catch to any trainer: giving the Pokémon a berry will have Shuckle turn it into berry juice. Wait even longer and that berry juice becomes a Rare Candy, capable of increasing any Pokémon's level by 1.

6 Unown

The Unown made their first major appearance in the third Pokémon movie: "Spell of the Unown". The creature resembles a letter of the alphabet, or the question mark or exclamation point symbols. As such, there are actually 28 different varieties of the PokémonWhen together in a large group, the Unown are powerful enough to distort reality to suit the dreams and wishes of whoever controls them, though they themselves are fairly weak.

Unown tend to live in their own dimension, rarely entering the Pokémon world. When they do make their appearance, they tend to stick to walls like ancient text or orbit other Unown, being very timid in character. The creatures have been show with the power to perceive the feelings of others, including both Pokémon and human beings.

5 Aegislash

Pokemon Aegislash

Aegislash - the Royal Sword Pokémon - is a creature that is known for attending and serving generations of kings in the Pokémon world. As legend tells it, whomever Aegislash recognizes as worthy is destined to become king.

What makes this Pokémon truly unique is its capability to change its form in battle, based on the moves it uses. For offensive attacks, Aegislash enters Blade Forme in which it carries its shield in one arm and exposes its blade. For defensive moves, the creature uses its Shield Forme, holding its shield in front of its blade and crossing its arms behind it. Aegislash is also the only known Pokémon to be able to use King's Shield, a powerful protection move that will lower the attack of any Pokémon that makes contact with the user by two stages.

4 Rotom

Pokemon Rotom

Rotom is another Pokémon with the ability to change its form, although it does so in a rather different manner. By possessing the motors of various appliances, the creature can change its appearance and typing at will. While the creature's base form is made of plasma, it can take the shape of a microwave oven, refrigerator, washing machine, electric fan, or lawnmower.

In every game since Rotom's introduction, there must be a room filled with these appliances where the player can take their captured Rotom if they wish to change its form. In this way, the Pokémon is more of a hassle to change than most of the transforming creatures. In the anime series, Rotom is shown as a prank-loving Pokémon who also has the ability to travel through time.

3 Volcanion

Pokemon Volcanion

The only fire/water Pokemon type in existence, Volcanion's reveal had a lot of players very excited. Unfortunately, the mythical Pokémon is not yet available to catch in any of the current games although it is the last creature in the Central Kalos and National Pokédex.

Volcanion has a unique organ, capable of turning nearby water vapor into hot steam in an instant and expelling that steam at incredibly high pressure allows the Pokémon to blow away whole mountains. In Southern Kalos, Volcanion is even worshiped for creating the plains in which the humans now live. If rumors are true about Pokémon Sun and Moon being set in a tropical area, it's no stretch to imagine that Volcanion may be making it's appearance as the Pokémon that created the new island.

2 Shedinja

Pokemon Shedinja

A creature based on the discarded skin of a cicada, Shedinja is a Pokémon that can be obtained by evolving a Nincada into a Ninjask whilst there is an extra space in the player's party. Shedinja has a hollow body, containing no internal organs, and a hard outer shell which floats without moving its wings. According to the Pokédex, it is believed that this Pokémon will steal the spirit of anyone peering into its hollow body from the crack on its back.

Shedinja is also unique in being the only Pokémon to have the ability Wonder Guard. This ability makes Shedinja immune to all attacks that are not super effective against it, giving the Pokémon an incredible defence against many creatures. However, Shedinja cannot ever obtain more than 1HP, meaning that even one connected hit will spell the end for the Pokémon.

1 Mewtwo

Fan-favourite Mewtwo was brought into the spotlight in the first Pokémon movie where he lured the strongest trainers to him, in order to prove that he was a better Pokémon master than any human. Since then, the Pokémon has made many appearances in media, including returning as a veteran character in the Smash Bros. franchise.

Mewtwo is one of the few Pokémon so far to have two different Mega Evolutions, depending on the held Mega Stone. It is also one of the very few man-made Pokémonbeing a clone of Mew created by scientists that wished to control the creature's power. Mewtwo is revealed to have yet another form in the upcoming Pokken Tournament where it will transform into Dark Mewtwo and join the fight as a secret playable boss character. So far, nothing is known about the mysterious new Dark form and Mewtwo is the only creature that we have seen take it on.

Ditto

Pokemon Ditto

Why bother catching 'em all when you could just catch one and already have access to every Pokémon you could ever want? Ditto is a Pokémon that learns only one move: Transform. While this move doesn't do any damage, it does allow your Pokémon to transform into a perfect clone of your opponent's creature until the end of the fight. At this point, you can use the moves that your opponent's Pokémon has learned.

Ditto can prove very useful to breeders who are searching for that perfect Pokémon egg as, due to its transforming abilities, the creature can reproduce with nearly every other Pokémon when placed together in the Daycare. There's a popular fan theory surrounding Ditto that believes the creature to be a failed attempt at cloning Mew before Mewtwo was created. This is due to Ditto and Mew sharing the same weight and color palette (both in shiny and non-shiny form), as well as both being the only Pokémon to learn transform.

While some are quick to criticize The Pokémon Company's work with some designs, there's no doubt that the majority of the 722 creatures currently revealed took a lot of work to produce. Honestly, when it came down to it, narrowing down the list to just 10 unique Pokémon was quite the challenge which says a lot about the amount of effort and imagination that has gone into creating such a diverse and interesting world.

Here's to hoping that Nintendo hits it out of the park with the new additions brought in by Pokémon Sun and Moon, as well as with any future Pokémon projects, of which there will surely be many.

Are there any Pokémon that you'd put on your own Top 10 Unique Pokémon list? Leave us a comment and let us know.