Sketch your design on a piece of paper. Bold designs work best as they have less complex twirls and other features that will need cutting and shaping in the finished product. Draw the size and shape of each individual piece of the animal you will be building onto different sheets of paper, using your original sketch as a guide.
Cut out the shapes you drew and use these as stencils to draw your shapes onto your sheets of metal using a pencil or whiteboard marker pen. You should now have a series of metal shapes to cut out that, when assembled, will form a recognizable metal art animal in 3-D.
Cut out your metal shapes using your hacksaw. File off any rough surfaces using a metal file. Place the pieces on a hard surface such as a portable anvil and bend them into shape using a hammer. When all your pieces are prepared, weld them into position. Allow the metal art animal to cool before touching.