Not Implemented/Still Considering

• Amaura Ice/Electric or Ice/Dragon Variant; or a better special rock move.
• Cranidos with RockHead
• Archen with SkillSwap or Entrainment
• Kabuto/Kabutops with more slash moves
• Lileep with Strength Sap
• Skitty with fairy typing and Pixellate/Normalize as its two abilities instead of Cute Charm/Normalize
• Golduck as Water/Psychic
• Goodra with a second type (Water, Poison, Bug)
• Electrivire with Fighting Type
• Magmortar with Dark Type
• Stantler with Psychic Type, or Stantler and Wydyr Ice/Psychic
• Volbeat/Illumise Variant Form with Electric type (Require new moves to make use of it)
• Arbok with Dark Type
• Ninetales with Ghost Type (Fairy, Dark also valid)
• Reuniclus with Water Type
• Blissy with Fairy Type
• Shinx with Dark Type
• Blitzle with Dark Type
• Bounsweet/Tsareena with Fighting Type
• Shuppet with Bug Type (Infected disembodied hand in a sock puppet) or Dark or even Normal
• Rillaboom with Normal Type (For sound move stab)
• Grapploct with Water Type
• Axew variant with Dragon/Steel instead of Dragon/Ground
• Tynamo with Water Type
• Falinx with Big, Dark, or Steel Type
• Sir-Fetched with Flying
• Misdrevus and Mismagius with Psychic Type
• Samurott with Fighting Type (Fighting > Dark > Psychic > Fighting)
• Emboar with Dark Type (Fighting > Dark > Psychic > Fighting)
• Serperior with Psychic (Fighting > Dark > Psychic > Fighting)
• Celebi with Fairy Type
• Mew with Fairy Type
• Manaphy and Phione with Fairy Type
• Meganium with Fairy Type
• Feraligator with Dark or Dragon Type
• Typhlosion with Ground Type
• Blastoise with Steel Type
• Absol with Normal or Fairy
• Dunsparce with any type other than normal (Ground/Fairy? Ground/Dragon? Ground/Normal?)
• Yanma with Dragon Type because it is a Dragonfly (Possible if Flygon goes back to being part ground, and Garchomp goes to being part steel)
• Larvitar as rock/dark to match tyrannitar
• Ponyta as Fire/Fairy
• Dratini line with Water Type
• Krabby with Steel, Normal, Ground, or Fighting Type

Implemented

• Chimecho Psychic/Normal with type conversion abilities (ie Conversion, Conversion 2, Reflect Type; can leverage Synchronoise) Equally valid would be Psychic/Fairy or Psychic/Steel, but Chimecho actually has normal type moves already.
• Flabebe line with grass Type
• Sunflora with fire Type and corresponding moves
• Masquerain with Water Type instead of Flying
• Houndstone with Rock Type (Ground would have been equally valid)
• Corsola/Cursola with Rock Type
• Gothita line with Dark Type
• Milotic with Fairy (After analyzing whether Fairy or Dragon was better, she has more fairy moves)
• Flygon as Bug/Dragon

Why Did I Do This?

• Vanillite Can anyone explain to me why I made them Steel. What Reddit post was I on at 3 in the morning that caused this to happen. Vanillite has no moves from any other type, it is clearly a straight ice type. Additionally, alolan vulpix already has ice/fairy special attacker cornered. Was I just trying to hit all the rare types?
• Skiddo Why are these now type ground. Is it because only Torterra has this type, and I was hitting rare types? I get that it's a mountain goat, but would rock not have been better?

Dual Type Information

Missing Dual Types in Pokemon

• Normal/Bug
• Normal/Steel
• Norma/Ice
• Normal/Rock
• Bug/Dragon
• Rock/Ghost
• Ground/Fairy
• Poison/Ice
• Fairy/Fire

Unique Type Combos

• Normal Ghost (Zorua)
• Normal Water (Bibarel)
• Fighting Ice (Crabominable)
• Poison Normal (Shroodle)
• Poison Flying (Zubat)
• Ground Fighting (Great Tusk)
• Ground Psychic (Baltoy)
• Rock Fighting (Terrakion)
• Rock Dragon (Tyrunt)
• Rock Dark (Tyranitar)
• Bug Ghost (Shedinja)
• Bug Dark (Lokix)
• Bug Fairy (Cutiefly)
• Steel Poison (Varoom)
• Fire Normal (Litleo)
• Fire Steel (Heatran)
• Fire Water (Volcanion)
• Water Steel (Empoleon)
• Grass Ice (Snover)
• Electric Normal (Helioptile)
• Electric Poison (Toxel)
• Electric Ghost (Rotom)
• Electric Fire (Rotom)
• Electric Psychic (Alolan Raichu)
• Electric Dark (Morpeko)
• Ice Ground (Swinub)
• Ice Bug (Snom)
• Ice Ghost (Froslass)
• Ice Steel (Sandshrew)
• Ice Fire (Darmanitan Galarian Zen Mode)
• Dragon Fairy (Mega Altaria)
• Dark Steel (Pawniard)
• Dark Fairy (Impidimp)
• Fairy Fighting (Iron Valiant)

Additionally there are some types where either only legendaries have the type, or only one normal pokemon has the type but legendaries do, such as Draglge with Poison/Dragon or Galarian Slowbro with Poison/Psychic.