Many of the enemies are animal like.
Some enemies are real animals, like snakes.
There is a heard animal called a Yakow that you hit to corral into its pen. However Yakows cannot die.
I can't remember with confidence if this game specifically breaks the fourth wall. But the Jak series as a whole is known to be cheeky, with a scene in the third game that fully breaks the fourth wall. Concerned parties should treat the dialog in this game with caution.