Step #1
First start the tutorial by drawing an oval & a triangle. Also draw a curve line.
Step #2
Make outline for fins and draw a single straight line.
Step #3
Make eye, mouth & upper part of the head.
Step #4
Draw outline for body.
Step #5
Make tail & gill shape as shown.
Step #6
Make fins.
Step #7
Draw moustache & flat shape over the gill as shown.
Step #8
Draw lines all over the body and tail as shown.
Step #9
Finally, make necessary improvements to finish.