With more than 800 Pokémon out there, you’d expect that every possible type combination had been hit already — and multiple times at that. A chart by Reddit user IanMazgelis proves that notion wrong, however, pointing to several Pokémon that stand alone in their typing, while also highlighting the type pairings that still have yet to appear in-game.
The chart below is missing a few Pokémon, as commenters pointed out in a Reddit thread; these include Drampa, the only normal/dragon-type; Rotom, the only electric/ghost-type Pokémon; and Kyurem, a legendary Pokémon with a rare ice/dragon typing.
That aside, it’s a comprehensive look at the most unique Pokémon in the series. Among them are the grass/ground-type Torterra, the final evolution of Turtwig, one of the three starter Pokémon available at the beginning of Pokémon Diamond and Pearl; the Alolan version of Raichu, who differs from its original, Kanto region edition by becoming an electric/psychic-type; and the especially odd Volcanion, who is somehow both a fire- and water-type.
As for the unused type combinations, we’re still waiting to see a Pokémon that’s both a fire- and ice-type, poison- and steel-type, bug- and dark-type and a few other pairs. Surprisingly, there has yet to be seemingly obvious fighting/ground-type or several combinations with the basic normal-type, but many of the other truly rare type combos represent opposing types.
As cool as it would be for a Pokémon to be both fire- and ice-type, it seems unlikely, as ice-types are weak to fire-type Pokémon, which would give such a Pokémon an extreme advantage. Also, that pairing sounds biologically ... impossible. But when it comes to Pokémon, the idea of biological plausibility is thrown out the window.