FINAL
ADOBE ILLUSTRATOR

First, you need to use the pen tool to trace the image you draw.

 Then, colour according to your like

 But remember that need to put shadow and outline

After done , save in JPEG file and the Ai part is done ,now we need to go to PHOTOSHOP!

AFTER place the image in photoshop ,Cut the image and put in another layer by using quick selection tool.Then, place the gear image.

 After arranged well ,put the rainbow background.

 Then use the screen effect.

 THEN, put the background you like and adjust the level.

Almost forget this, if you can notice that the teeth of my elephant have some different. Yeah! I cut the teeth shape in the image  and put inside. Extra , don't forget to put some shadow.

FINALLY