Which pokemon could do with a type change?

[Ark Kuvis]

I always wanted a Gen 1 pokemon to get a dark type, since Gen 2 introduced Electric/Steel Magnemite. Maybe make Oddish pure grass, then make Gloom and Vileploom Grass/Dark, and Bellosom pure grass. IDK just a thought.

Also, Serperior for Grass/Dragon, Emboar for Fire/Dark, and Samurott for Water/Fighting. It works out so much better this way.