The proportions for the Q-Bert as put forth by the game itself are clearly unrealistic: For a creature of the Q-Bert's relative size to remain bipedal, the legs would have to be much longer and the body a bit sleeker. This build can be seen on several other existing animals, such as the ostrich or emu. The nose, or "trunk" is clearly a similar appendage to that of the anteater, however, the opening is far too large for the two creatures to share a similar food source. The Q-Bert probably needs a nutrition source much higher in protein to maintain its famously manic energy level (the only means of locomotion for the creature is constantly hopping, and it is frequently found leaping up and down what appear to be Mayan Ziggurats while swearing prolifically at snakes).
When taking into account both the relative size of its "trunk opening" and the dietary needs required to sustain such a creature's lifestyle, we can deduce both that the Q-Bert is a carnivore, and that its diet is mostly rodents, small-to-medium sized mammals such as rabbits and the occasional young offspring of larger prey animals. In short, the Q-Bert is most likely a carnivorous, earthbound bird-like creature that eats adorable woodland creatures while calling you a motherfucker.
It's commonly assumed that Mega Man was an accurate simuloid of a human, and the rather bizarre, infantile appearance of the robot in the actual games is chalked up to the limited graphic capabilities of yesteryear. But keep in mind that modern-day androids designed only to accomplish one task--to look human--still fail catastrophically at doing so. They always fall into the realm of unsettling disbelief we call "the uncanny valley." For an android of Mega Man's functionality--specifically a hunter/killer of rogue robots--it is unlikely that appearance was a primary consideration; functionality would be valued much higher than the ability to pass as human. Specifically, the functionality to steal other robots weapons and ironically beat them to death with their own devices.
Look at the original sprite:
Its facial features are roughly 70 percent eyes. Being a visually oriented hunter, this is clearly a valuable asset. We can also see the relative size of the mouth is greatly exaggerated. This suggests the Mega Man robot was likely powered on some sort of bioreactor, where the gaping mouth would allow the maximum flexibility in consuming energy sources. Look at the size of the energy containers, for example: They are roughly the width of his entire body. In order to consume power-ups like these, the Mega Man must have had the ability to unhinge its jaw, much like a snake, to accommodate the largest possible energy refills.
Please try to avoid picturing Mega Man deep-throating this.
The non-gun hand is often interpreted as a balled fist, but another quick glance at the sprite itself will quickly disprove this theory: The "hand" in question is clearly a tapering shape that bends up and forward, reaching out from the forearm. This "hand" is probably something akin to a lobster-like fleshy claw in actuality. This makes design sense as well, as it would be ideal for crude grappling, and capable of the crushing force a hunter/killer robot would need to pierce armor plating. By looking at the original sprite, one can also see that he apparently has a floppy blue dong on his helmet. The relevance of this last fact is debatable, but just try to unsee it.
Space Invaders are thought of as "cute" or at the very least "relatively harmless" because of their small, simplistic design in the video game. This is far from the case, however. If the triangle is meant to be an anti-aircraft gun, and the blockades are meant to be bunkers, this would put the relative size of the typical Space Invader about on the level of a very large truck or small building. Keep in mind these creatures are not spacecrafts: Actual alien ships do make an appearance in the game as saucer shaped objects, but they are entirely separate entities. The Space Invaders themselves are living things designed to survive the harsh environment of space, whose primary purpose is the invasion and destruction of other civilizations. Thus, we can look to other similar super-predators for traits similar to the Space Invader.
The appendages emerging from the bottom of the front-most, "head" portion of the sprite are often thought of as arms, but it is far more likely they are actually mandibles like those of a large spider. Notice the overall structure of the eyes; largely vertical. This suggests they have more in common with a feline eyes than those of a deer or rabbit, for example. Again, this makes sense for the utility of the creature: Space is a very dim place, and predators spending any amount of time there would naturally have a more nocturnally-tuned vision system. The appendages emerging from the top of the head are widely considered to be antenna, but then this would cause the Space Invader to be a bipedal creature (only the two side legs remain for locomotion if that were the case). The considerable bulk of the Space Invader makes this unlikely. No, it is far more plausible that the Space Invader is not actually depicted from the frontal perspective at all, but from a top down view; its four legs spread wide for stability while it descends--like a spider on a thread--with its mandibles open in attack position.
Link, like Mega Man, is another victim of humanity's tendency to anthropomorphize. Yes, he is most certainly a humanoid creature, but that does not mean his many grotesque mutations from the human form can simply be ignored. Let's begin with the ears: Notice where they are situated on the head. They are not centrally located on the side of the cranium like a human ear. They actually seem to sprout from each side of his lower jaw, and rise up and backward from there. The eyes appear to be delineated into two separate sections and are more vertically oriented than a man's. Rather than explain this away by saying it was simply a baffling attempt at depicting a pupil and iris using only two pixels, it is probable that we are actually dealing with two separate sets of eyes.
The general conception of Link is that of a thin, short-statured boy. While the "short" descriptor is likely true, the "thinness" is probably just an idealization of form. In-game, Link is depicted as a formidably stout, thick creature. His limbs are far shorter than a human's, the torso is full and squat; this build is more like that of a badger or wolverine than a primate. This body-shape would give him maximum leverage (which makes logical sense when you consider that most of Link's time is spent pushing and pulling heavy stones), as well as enhanced stability when facing aerial or jumping foes, like those fucking asshole spider things that always show up when you have half a heart left and you've been listening to that goddamn beeping for like an hour now and you finally - finally- cracked open a pot with a heart in it, only to die at the last possible second from getting pogoed on by a frickin' jacked-up crab.
Much like a shark, Pac-Man was a predator who relied on his mouth as his sole source of attack. This would put the tender areas of his face in danger, so it's likely that his large, black, shark-like eyes would also have the shark's trademark filmy secondary eyelid to close over before striking. Though he was a fearsome hunter, Pac-Man was also an omnivore--he fed off live prey as well as vegetation (see cherries).
Therefore he probably had a set of teeth quite similar to a human's: Longer, sharper incisors to the front, with molars to the rear. Because Pac-Man didn't have the razor-sharp claws or other grabbing capabilities we see in most land-based predators, he probably ate most like a snake. This connection strengthens when you notice his trademark gaping maw, which allowed him to swallow prey more quickly and use his stomach to do most of the digesting. This also accounts for the unusual shape of Pac-Man: We're only familiar with the fuller, rounder body because his handlers obviously wanted to use a sedated, well-fed creature during gameplay to help limit aggression and the potential for violence. In reality, the version we are accustomed to would only be seen in a creature that had recently caught a meal. Between feedings, Pac-Man's bulk would be in the form of a deflated cylindrical trail of loose skin, most resembling a used skin-condom.
The Pac-Man's primary food source, it should be noted, is the souls of the recently deceased. When grandpa "passes on," it's possible that instead of "going to a better place" he is actually quickly chased down a dark, twisting crypt corridor by an orb of teeth, before ultimately being torn apart and digested; only his eyeballs left to be callously crapped out onto the cold stone floor.
Supplementary Information: The female of the Pac-Man species is often distinguished by the adorable "bow" on her head. This is another case of dangerous anthropomorphization: The "bow" as we call it, is actually a brightly colored crest. Bright colors and elaborate appendages in nature are often a warning sign to potential predators that the animal is venomous, and to stay away. Nature expert R. DeVoe, formerly of the New Edition Digest, famously authored a report on this phenomenon in an expose published in the early 90s, where he also warned of the female's deviousness by insisting that the creature's elongated teeth, substantial girth and streamlined anterior were all further indicators that one should be wary. This was the "Never Trust a Big Butt and a Smile" system of threat identification as outlined in his greater "That Girl is Poison" treatise.
*Mr. DeVoe was assisted in his research by the esteemed Dr. Biv and Prof. Bel of the New Jack Swing University.