Evidence and source material: Fallout 3

Why they’re superior: Eight feet tall and made of green, Super Mutants are what every little boy wants to grow up to be. Once these towering-hulks were ordinary humans, but they were transformed after the nuclear holocaust. Now they roam the wasteland doing whatever they feel like doing, because they wear used car parts as armor.

The downside: They smash people with hammers and then put them in bags.

Above: What should we do with this bag of mutilated human? Let’s hang it up in the air

Will they replace us? After the end of civilization, people with the appropriate genetic predisposition will go green and launch the campaign to end people. Sending organized forces to battle Super Mutants in full suits of power armor, equipped with mini-guns and inventories fully loaded with stimpacks hotkeyed to every single button, might work. But the best plan is to get someone to level 20 and send him or her out alone. Tell the hero to figure out where they’re coming from and give them explicit instructions to do this:

Evidence and source material: Left 4 Dead

Why they’re superior: Another species belonging to the "formerly human" crowd, these walking corpses aren't afraid to get stupid. They take a hit in the cognitive thinking department, but the undead really excel when it comes to digesting difficult-to-eat meats, not caring about what others think and the ability to hold their breath for a really, really long time. That’s like a three-for-one deal.

Above: They’re less pretty, but it doesn’t bother them

The downside: Being not alive means that the undead have started decomposing. If there's one thing we've learned is not sexy, it's being partially decomposed (and we only had to learn it once).
 

Above: A smokin’ hot undead babe

We’re kidding. Zombies are not sexy.

Will they replace us? If numbers count when calculating the new ruling race, consider that the undead have everyone who’s ever died on their side (e.g. most people), so that’s an advantage. Plus, if they so much as cough on your BFF’s paper cut, shortly afterwards your friend will almost certainly gnaw your nose off.

If games like Left 4 Dead can teach us anything, it’s that we've still got a fighting chance, so long as the heartland doesn't stop leaving open weapon cabinets and piles off ammo lying haphazardly around farmhouses, and city subway cops continue to be armed with assault rifles and automatic shotguns.

Above: The second amendment is also to protect us from the undead

Evidence and source material: Too Human

Why they’re superior:  Too Human = not robot enough.
 
Robots are made of metal, often square, and go “bleep, bleep, bloop,” so duh, everyone wants to be a robot. Even the Gods in Too Human have hardware envy. They were once just regular people, longing to add circuit boards and LED lights to their faces, so being men and women of action, and recognizing a superior lifestyle, they cybernetically enhanced themselves enough that nobody said anything when they began referring to themselves as Gods.

Above: We’re screwed

Actual born and bred robots, like the big one in the picture above, forgo the few flesh and blood necessities the Gods still retain and really commit themselves to being made of metal.  It’s an admirable quality, and if machines didn’t always wind up harvesting human blood and limbs for reasons that don’t make any sense under scrutiny, we could almost co-exist peacefully with our electronic brothers.

Above: Someday, it will harvest your organs, and then heat them rapidly

The downside: Not only will we be replaced, but if Too Human is right, they’ll take all our cool mythological creature names. Robots will obnoxiously force humanity to refer them as goblins, dark elves, undead and who knows what else, even though everyone will know robot elves are absurd.

Above: One of these things is not an elf

This illogical behavior will grate away at our self-worth, common sense and canon of commonly acceptable Western names, but that mostly just applies to those who aren’t harvested for their fluids.

Will they replace us? Whether it’s an invasion of robotic hordes from the frozen, unexplored northlands or all the microwaves simultaneously turning on hi-power and flinging their doors open to rump-roast our faces, the robots will make a grab for supremacy.  Be ever vigilant against our electric rivals, and humanity may stand a chance.