Step 1: Start by drawing a large, round eye.
Step 2: Draw the top of the head as a bent coat hanger, going straight over the eye at an upward angle only to be bent downwards in an arc later.
Step 3: Create the gill cover by drawing a wire bent over on itself on the lower half of the face.
Step 4: Draw the mouth as a set of inward slanted lips at the left meeting point of the gill cover and top of the head.
How to Draw a Tilapia Face – Step-by-Step Tutorial