The rapesnakes in general strike me as the Gods' first stab at imbuing ambition in creatures. A bunch of the other senet beasts seem to incorporate some aspect of the human soul in their behaviors, based on what we see.
Mountain Ogres: kinship, kindness, protective nature; they literally went extinct of saddness
Nereids/Slyphs: lust, curiosity, and playfulness
Ilganyag: a sapient proto-human with some degree of fondness for others, but is mostly concerned with the acquisition and perpetuity of knowledge. Possibly self-serving, she nonetheless seems to see the advancement of knowledge as an end unto itself. She would represent human intellectualism and self-improvement, she's where the Gods got crafty with how their creations think and apply themselves to their goals.
Efheby: Another sapient senet, efheby seem to embody every possible ambition, along with amped up drive, decreased morality, and fierce territoriality. Like Ilganyag, Ruck seems to lust for knowledge, but more for his own sake than any high-minded intellectualism. He wants the knowledge, wants to own it, to make it his. He's driven by his nature to acquire resources, whatever they may be, and defend them. When he and, presumably, other efheby take interest in a person, they want to make that person theirs; they take them in every way possible, they rape them, eat their memories, and devour their bodies. They seek to wholly possess all that they can at the expense of others.
I can see why the Gods seemed to settle for humans, since we sort of take the best from all prior creations and lock ourselves in a self-perpetuating cycle of misery and despair.