"Chemicritter" (化合獣Kagōjū, "Chemical Beast") is an archetype of Level 2 and 8 Gemini monsters with multiple Attributes and Types that first appeared in Invasion: Vengeance.
So far, all Level 2 "Chemicritter" monsters' combined ATK and DEF equal 2100 while the "Poly-" ones (Level 8) equal 3000. One oddity is that along with multiple Attributes and Types, many members have a combination that is rare in the game, such as Aqua combined with FIRE and Beast combined with WIND.
"Chemicritter" monsters are named after a chemical substance and an animal, while "Poly-Chemicritter" monster are given names that are a combination of two creatures (eg. Hydra + Dragon). Each member of the archetype has a symbol(s) on their bodies to represent the chemical substance that they are based on, e.g. "Hydron Hawk" having the letter "H" on its chest to represent its hydrogen basis.
The main strategy of "Chemicritters" is to summon their Gemini monsters and give them their effects, while ultimatively focussing on a Beatdown strategy. As with any Gemini monster, "Chemicritters" need to be summoned twice to become Effect Monsters, but both the archetype itself and some generic support help with speeding up that process.
The three Level 2 monsters of the archetype are all helpful in their own way: "Chemicritter Carbo Crab" is a "Foolish Burial" for Geminis combined with a search effect, and both help the archetype immensely; "Chemicritter Oxy Ox" is a Special Summon assist for the bigger Gemini monsters as well as a Level manipulator to go into Rank 8 monsters; and "Chemicritter Hydron Hawk" further fills the GY with cards due to its discard cost and then revives Gemini monsters from the GY. The "Poly-Chemicritters" should not be underestimated either: "Poly-Chemicritter Dioxogre" is one of the major beaters in the deck and upon activation as an effect monster, it blocks Normal Summon negation and brings a much-needed destruction effect, all while producing further setup for the second effect of "Burnout". "Poly-Chemicritter Hydragon" is the defense wall of the deck and brings protection and stat boosts as an effect monster. All of the work towards a Rank 8 monster normally ends in "Vola-Chemicritter Methydraco", who brings a trio of effects in form of revival, protection for Gemini monsters and non-destruction removal to the table.
While the effects of all monsters in the "Chemicritter" archetype can be labeled as good, the main problem still is the Gemini part. With only one Normal Summon per turn, Geminis are probably the slowest Summoning type in the game. Fortunately, Konami was aware of that and made "Catalyst Field": This card is absolutely paramount for the deck and should be on the field at any point in time. First of all, "Catalyst Field" allows the Normal Summon of higher Level Gemini monsters without Tribute, which allows cards like the "Poly-Chemicritters", "Phoenix Gearfried" or "Darkstorm Dragon" to be put on the field without a huge minus in card economy. Secondly, "Catalyst Field" is a "Double Summon" for Gemini monsters. This means that you can summon two "Chemicritters" for a Rank 2 Xyz or a Link-2 monster, or summon one of the bigger members and a smaller one, or you simply summon any of the Geminis and activate it as an Effect Monster right away. And lastly, "Catalyst Field" has an in-build destruction effect, which is costly but helps in certain situations.
Aside from "Catalyst Field", there are other useful options for this deck to consider. "Supervise" is a very powerful card, since it not only activates a Gemini monster instantly, but also Special Summons a monster from the GY when "Supervise" leaves the field. "Blazewing Butterfly" was a decent option to get monsters back from the GY, but the newer "Evocator Eveque" does that job even more efficiently, even though he does not grant the summoned Gemini its effect. The aforementioned "Phoenix Gearfried" also revives monsters and further helps ironing out some of the consistency issues, while "Darkstorm Dragon" is technically a walking "Heavy Storm" and therefore a godsend against certain matchups. Even the bigger version of "Phoenix Gearfried", the so-called "Immortal Phoenix Gearfried" can be an option for the deck, since "Supervise" becomes completely useless once it hits the GY; with either "Hidden Armory" or just a touch more Equip Spells, you can unleash the "Thousand-Eyes Restrict"-like beatdown and negation machine that is "Immortal Phoenix Gearfried".
Other Spell and Trap options for the deck are "Trade-In", since a lot of the monsters will be Level 8, "Terraforming" for easier access to "Catalyst Field", "Burnout" for summon shenanigans and "Gemini Ablation" for easy access to pretty much anything of relevance in the entire deck. Since Gemini monsters are treated as Normal Monsters in the GY, a number of cards can interact with them. "Dark Factory of Mass Production" brings two Geminis back to the hand, while "Tri-Wight" revives three of your "Chemicritters". "Silent Doom" and "Swing of Memories" can both work as multiples of "Monster Reborn" with slight drawbacks. "Dragon's Mirror" is especially helpful in certain situations: It allows for the Summon of a Fusion Monster by banishing the materials from the GY, giving access to "Superalloy Beast Raptinus" to unlock the effect of every Gemini monster or "First of the Dragons", who can counter a number of monsters.
Since "Chemicritters" already work with a lot of Gemini cards, be it monster or support, they can work equally well with other Gemini archetypes. One example for such a collaboration is "Red-Eyes": "Red-Eyes" cards put insane amounts of monsters into the GY, a quality "Chemicritters" would like to have and actually do profit from. "Red-Eyes Archfiend of Lightning" has a "Raigeki"-esque effect while "Red-Eyes Black Flare Dragon" can potentially deal a ton of damage. "Red-Eyes Insight" fills the GY and fetches cards like "Red-Eyes Fusion" with which "Meteor Black Comet Dragon" can be summoned, further setting up the GY while dealing burn damage and even bringing back Fusion Material if it is destroyed. Due to the fact that the opponent will try to eliminate your "Catalyst Field" whenever possible, "Mana Dragon Zirnitron" will be triggered. It won't bring "Catalyst Field" back, but 2200 ATK with the ability to re-use any other Spell or Trap card might still be worth it. Also, since "Red-Eyes" bring more different Levels to the party, "Reasoning" can be a valid choice. Furthermore, "Red-Eyes" do actually open up Rank 7 as a toolbox, which means that "Number 11: Big Eye" and "Red-Eyes Flare Metal Dragon" can become members of the Extra Deck, while "Tenyi Spirit - Vishuda" can join the Main Deck both for potential Xyz Summons as well as for its effect.
"Chemicritters" rely on their Field Spell "Catalyst Field", so any cards that can destroy Spell Cards like "Heavy Storm Duster", "Twin Twisters" or "Cosmic Cyclone" can slow them down immediately.
Furthermore, the deck works completely around its monsters and their effects, making board-clears like "Raigeki", "Dark Hole" or "Interrupted Kaiju Slumber" an effective strategy.
Since Gemini monsters lose their effects upon being turned face-down and "Supervise" leaving the field for not equipping a legal target, any cards like "Book of Eclipse" or certain "Ghostrick" monsters counter "Chemicritters" hard.
