I feel kinda bad asking another for a further iteration of this thing, but he must be Perfect.

It can switch between biped and quadruped movement. But mainly I'm concerned about the quadruped stance. I need to determine how realistic is the head and neck size in proportion to everything else? Will it be easy to hold up? Any issues? No falling forward?

Additionally, during biped stance, it is about 4 feet tall from foot to top of head. I give this because I'm not sure if overall size matters in this. Does a creature need taller spinous processes for hold up head muscles as it gets overall bigger; not just head size?

I used hyena images for reference drawing this, due to head similarities and bite strength. Basic bone structure is shown. Is primarily biped so hips are biped hips. Got spinous processes tallness shown. Neck shows nuchal ligament. Feet are chicken foot shape. Back toes don't actually point straight back; didn't know how else to show they are there. I know I could just lengthen the body but then it doesn't look right in biped stance.

Any additional improvements are welcomed and encouraged. My hyperfixation baby must be Perfect.

Here he is My boy Ignore white smudge

Slightly altered, improvements? My boy 2

Partial shoulder structure in biped mode facing forward Forward biped

Ugh social anxiety is pain. I have a hard time functioning with communication; anxiously waiting for it, on this site and I'm tired. I've got a confession to make. He's a shapeshifter. But shape shifting costs energy, so I wanted to see how little as possible he'd have to change in order to transition between biped and quadruped mode. Be more efficient. My main goal here was to make sure that the head and neck weren't too proportionally big compared to the rest of him; no balance issues; no excessive strain due to weight; etc, during quadruped.

  • $\begingroup$ The rear foot seems far behind the hip as if mid-step. I guess the centre of mass is further back than can be seen from the drawing if the tail is muscular and long. - Is that an opposable thumb on the back foot I see? $\endgroup$ Dec 1, 2021 at 0:01
  • $\begingroup$ @ARogueAnt. oh shoot that's not a tail its the legs in biped position I should edit that out. $\endgroup$ Dec 1, 2021 at 0:04
  • $\begingroup$ @ARogueAnt. The back foot is positioned further back because of the long back legs needing to bend more to accommodate the length. The back toe is a bit uncomfortably placed; doesn't usually bend straight backwards, but I felt it important to know its there. $\endgroup$ Dec 1, 2021 at 0:11
  • $\begingroup$ So @Chickenpeep as for the neck, consider rotation freedom of the head, sideward and forward. Bipeds need forward vision, not upward vision. This neck is quite short, to bend in all directions. $\endgroup$
    – Goodies
    Dec 1, 2021 at 0:13
  • $\begingroup$ @Goodies I thought I made it about wolf proportioned neck. What if it were a bit thinner? Or else how much longer? $\endgroup$ Dec 1, 2021 at 0:36

2 Answers 2


Mostly realistic - if there are reasons.

Regardless of whether an animal 'looks proportional' - probably a more important question is: what features are needed for the creature to be biologically more successful?

In other words you can overlook the following if there were reasons:

  • Hind limb long toe joint: Unlike most animals today, yours features a lower hind limb joint arrangement more like a kangaroo, with elongated toe structure forming the foot joint. Not unusual but does your creature need to 'leap'? Perhaps its food sources are far and between and of low calorie value, requiring coverage of long distances causing a more efficient movement structure is needed.
  • Quadruped movement: If your creature moves like a kangaroo, does it need such substantial forelimb structure for quadruped movement? A horse invests this because primary movement is on all fours. However, having said this there are many dinosaurs and mega mammals that do feature substantial forelimb structure but with extendable hind limbs, likely to reach high food sources.
  • Jaw structure is small: If your creature is overall 4 feet high (not much different to a dog) the jaw structure size seems more appropriate for a plant-eater, however graziers tend to have longer necks to access food on the ground. In your case, a carnivorous diet seems more appropriate, but with a small jaw structure (lacking in incisor bite ability) it may be more of a carrion eater instead - but again most carrion is on the ground and this creature would constantly be bending to eat.

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  • Your toe structure: looks more birdlike than animal like - however again this is not without precedent in previous megafauna. However extensive claws and rear toe with forward extended toes are usually features of birds due to the ability to cling to branches and spread weight efficiently. This is called a Anisodactyl layout. It however does not make much sense for an animal on the plains, or amongst rocks, as the rear toe is not needed to perch, and also most birds are bipedal, meaning the toe is the only means to grapple. Your animal has 4 accessible limbs, so unless it uses its forelimbs to manipulate objects (like hands), an Anisodactyl layout on all 4 limbs or at all is most unusual.

As with all evolutionary quirks, you do get odd mutations now and then though, so anything is possible. However, sometimes as evolution tells us, it is better to optimise for need rather than cater for too many possibilities.

  • $\begingroup$ I tried to make the head proportioned like a hyena head, but with the snout a bit shorter. I can make the teeth bigger if thats what you mean. I didnt know how to show the back toe is there without drawing it pointing back; it doesn't actually have that feature. I said its primarily biped but can become quadruped. This is why the long hind legs. As I based it on some hyena features I noticed that hyena bodies are angled slightly upwards, so the long arms are to angle the body. This is an adaptable creature, can succeed in many environments. Can hunt and crush bone but will gladly eat carrion $\endgroup$ Dec 1, 2021 at 16:07
  • $\begingroup$ Neck length is for being able to hold it facing forward in biped mode; I thought I sized it like a wolf neck. Also will eat fruit and grains, but primarily eats meat. Has some climbing ability; has biped shoulders. $\endgroup$ Dec 1, 2021 at 16:13

The rear legs/feet are bad for locomotion. Think about the motion necessary to take a step as a quadruped. If the hips remain at around a constant level, which they do for pretty much all animals that walk, the flat of the foot has to stay parallel to the ground, thus the ankle and knee have to stay permanently flexed, which will place constant tension on the ligaments and muscles. You're also losing the advantage of the long foot in that it can't roll forward, efficiently transferring energy. Basically the only way it can walk without lifting the entire hip is to plant the foot and keep it flat until the entire foot is lifted and moved forward. In other words, it stomps around.

The only way for the foot and legs to work efficiently is to raise the hips with each step, providing enough room to swing the lower leg and foot forward, but that's inefficient because most of the energy would be used to lift the body vertically rather than move it forward.

To see what this would be like, look at kangaroos. They have a similar foot/leg structure but they can't walk, they have to hop and tend to be kind of slow and ungainly doing it. This animal, with this leg structure, would have to do the same.


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