To cover all other unused Normal type combos, I imagine another multi-evolution Eevee-like poke.
I picture a lego-based toy-like pokemon as the base. Similar to Eevee, it branches off to many other evos depending on whether it is evolved by different stones, locations (Ice Rock, Moss Rock, etc.), or friendship. Although, upon evolving, this poke keeps its Normal type and gains a secondary type.
Possible evos: Water Stone -> Lego-ized rubber duck-looking poke as Normal/Water Fire Stone -> Lego-ized fire lion as Normal/Fire Thunder Stone -> Lego-ized wind-up figure as Normal/Electric Leveled up in sand -> Lego-ized armadillo as Normal/Ground
Just a little idea I had. I think it would be nice to have another Eevee-like pokemon with multiple ways to evolve and cover some of the more unusual type combos.
3DS FC: 3437-4145-0175 PKMN White 2 FC: 0433-6133-8662