1, draw a triangle as the fish head first.
2. Then draw a fisheye on the fish head. As shown below.
3. Then draw a straight line and a tail triangle on the fish's spine.
4. Add some fishbones to the tail.
Finally, just draw the thorns on the fish.
Matters needing attention
1. To draw a fishbone stick figure, you need to master the fish's body shape.
2. On the fishbone, you can try to use some figures and lines.
3. The fishbone stick figure does not need to be colored.