Here are a few things I noticed while drawing Tweety's profile
Tweety's head is like a baby's head, its very human in the way it's constructed. Our craniums are designed to protect our brains, Tweety's cranium is curved in a very similar way.
The Cerebellum is the round point at the bottom back point of the brain, the farthest back point is curved to contain it. The highest point is at the top back part, curving down to the forehead, which contains the frontal lobes. The part of the forehead closer the the scalp is called Frontal Eminence, and the part of the forehead closer to the eyebrows is called Gabella, the middle part between those two looks a bit sunk-in on human profiles, it may be decorated with worry lines, depending on how optimistic you are.
In cartoons we curve that to look more appealing, Tweety's farthest (and curved) point would look flat or sunk-in on human profiles. His cheek follows a curve from the back of the head and the eye, it covers the eye a bit.
His feet can be thought of as flattened corn kernels, the flatter part being the heel, and the rounder part being the toes, separated by a center line. his toes reach his heel.
His torso can be seen as a fat bean, The fatter part being the tush. The curve is much like real babies, only exaggerated and cutie-fied.
His wings are like tiny chicken wings, no palms unless the scene calls for it. I find that a lot of curved shape can be sketched with a "figure 8" approach, it creates a pleasing silhouette which you can later "flesh out" by deciding where to overlap your finishing lines.