So ive been doing some thinking and ive seen that there are some existing pokemon who would match the unused type combos as of generation 9. so here they are:

Bug-Dragon - Armaldo (if it wasnt a fossil) and Slither Wing

Normal-Steel - Klink line

Normal-Rock - the most popular (and logical) choice is lycanroc

Normal-Ice - Cubchoo, Eiscue,Vanilite

Normal-Bug - Tarountula

Ground-Fairy - i dont really know for this but ive seen Phanpy maybe?

Fire-Fairy - this is hard maybe Delphox??? i dont agree with it bc its a witch and literally has psychic powers but i have no other ideas

Rock-Ghost - Sableye i mean, it lives in a cave which is made of ROCK it has ROCKS for eyes and when it mega evolves, it cuddles a giant ROCK. Also, Runerigus, greavard etc. (gamefreak are allergic to this typing it couldve been put on so many pokemon but no)

Ice-Poison - another hard one; the only one i saw was Hisuian sneasel and sneasler but even theyre a bit of a stretch