ITT: Previous gen evolutions that should happen. Bonus points for groups, coherent continuation of design and theme and thematically coherent increases in competitive viability.

Saw an anon post last week explaining that pic related are incarnations of air, water and land poisoning so I thought these types for the third stage would make sense.
Also a movie monster movie theme would be cool, with Garbodor-hedorah, the Blob Muk and I dunno for Weezing. What do you think?