Welllllllll. 

I love the art. I love the enthusiasm. They’re very unique combinations of Pokemon and I totally dig the designs people on Tumblr are coming up with that have a subtle mix of two species while clearly favoring one. They look super neat.

As far as legitimate Pokemon representations in the world, I absolutely hate them.

Pokemon already has a world of issues when it comes to biological terminology, and the definition of a species.

As far as taxonomy is concerned, a species is considered a group of animals that can successfully reproduce and produce fertile offspring. How horse + horse = horse that can make more horses, but horse + donkey = sterile mule. (This raises a funny question about species vs. race in scifi and fantasy, too, since humans/elves/vulcans/orcs all end up being the same species since they can produce fertile mixed offspring, but… that’s not what we’re here to talk about.)

So technically, every compatible egg group in Pokemon would be the same species… despite that every individual Pokemon is called its own “species” in the Pokemon world. This adds a powerful dynamic to evolution, since the change in a Pokemon when it evolves is much more significant than growth and age. (Granted, the Pokemon Tabletop pokedex opted to treat each evolution line as its own species, but I believe the game/anime canon calls each Pokemon its own species - or occasionally has pokemon that share a “species name,” i.e. Bulbasaur being the “seed Pokemon.”) 

But as far as the crossbreeds are concerned, the game already has a firmly established mechanic for how Pokemon breeding works. A male and a female Pokemon who share an egg group breed and produce an egg that matches the species of the female. Previously, only the male could pass on Moves (now both can, I believe, I’m not much into eugenics for my Pokemon so I’m not an expert in that department), but in modern breeding both parents can contribute Moves, Abilities, and Natures depending on the breeding circumstances.

There is no weird hybrid breed. There are egg groups that determine which Pokemon are compatible with one another. (I haven’t been checking if all the hybrids have been within the same egg group since I’m not about to grump on people’s fun, but somehow I doubt that all of them were.) Breeding produces a Pokemon of a single, distinct species that potentially exhibits unique traits from the off-parent.

I would be more interested in some of the art had the influences been a lot more subtle. Don’t get me wrong, it’s a difficult task to make a Pokemon design that only slightly alludes to a second species’ influence on its appearance. Some of the designs floating around are really indistinct looking hybrids that don’t identify with one species. If they were being branded as the pokefusions trend that went around a while ago, I would love them.