ITT: Create a concept for a pokemon that could take on a currently unused typing or a typing you think needs more representation eg- fire/water

Poison/Ice

Something like the dilophosaurus from Jurassic Park (the one that kills fatty).

A fossil pokemon that was originally pure poison, but due to the ice age was frozen in time until being recently discovered and recovered, gained it's ice typing by being unable to fully shake the effects of being frozen for thousands of years.

Dunno what to say in terms of stats, but something like this would probably be a speedy, frail attacker, possibly leaning more towards special attack because of spitting venom but could be mixed attacker.