This thread went way off topic! From perception to excretion ......... now you've come in with perception of excretion!
You may wish to follow your interest in animal defecation HERE!
As to shape, "what gives" is diet, bowel structure and retention time. A human may go "round pills", nutty lumps, "big plop", "weiners", splitters, cables, splatterers, liquid surge and, as you so poetically put it, "winners". Isn't this part of what makes us superior to mere animals? They tend toward rather monotonous patterns.
For animal enthusiasts, a handy key chain HERE.
Any questions? More info?
(I thought not!)