Leg talk

When drawing the legs or arms of a creature its important to keep in mind the animation and degree of movement the joints might need. Often you see hind legs on bipedal creatures drawn with hugely muscled areas which really  restrict movement -unless the animation system can deform the mesh or stop the parts intersecting- and if it does it can be a lot of work to set up.  One answer is to adjust the cross sections so they overlap and sit together nicely when the limb is 'closed'. Alternatively the angles one joint makes with another can be adjusted to allow the leg to close.

Keep in mind again the function of the particular limb.

Predators like big cats and dogs have forearms that are a bit similar to ours and can turn the palm or paw about the long axis of the arm, to assist with gripping prey , whereas horse and other prey animals  are more focussed on running.

The number of legs a creature has can affect its speed of movement. Seems obvious- the longer the legs the bigger the stride. four legged animals use the flex of their spines  to increase speed/stride , however if you have too many legs and as they increase in length (to increase stride and then speed) you can get problems with legs interfering with each other.  Giraffes are an example of a very large long legged animal- they have an unusual way of walking which might be to reduce this. At asmall scale there are fast moving centipedes that sort of push the limit of lots of long legs.

Legs aren't simply straight but have slight angles between them- sometimes its more pronounced. Often the bulk of the muscle is on the outer side of the bone (ie horses and dogs). Again the bigger and more massive earth creatures are the straighter their legs tend to be to support  them without lots of energy required.

Even in humans  as the legs get thicker on the inside the person has to adopt an unusual stance or way of walking. Bodybuilders muscle development forces their arms out in an at rest position for example. Obese peoples legs tend to appear to splay out or straddle because of a combination of the normal joint angle at the knee and the fat betweenthe thighs. Often characters can be drawn in a pose for modelling without enough leeway for free movement of the legs- so that when they are brought together in a more natural standing pose there are problems with the legs intersecting.  On the positive side having legs or body that forces a creature to move or stand in an unorthodox way could be part of its character that you want to keep.

Its also to keep in mind the range of movements a creature will adopt- and its helpful to do any explanatory drawings or pictures to explain how a creature moves or functions- but also to show its character. when adding spikes or horns its important to place them such that they don't interfere or restrict movement you want.