Step 1: MATERIALS
2. 14-16g wire
3. Plastic jar (e.g. peanuts, pnut butter, mayo)
Step 2: TOOLS
2. one finish nail
3. aviation snips
4. utility knife
Step 3: SKELETON
Cut away the top portion of a plastic jar and its lid. Start the initial wires through holes in the jar. These holes are punctured with a finish nail. In your strategy of forming the early wires, include a ring around the jar close to the lid. This will later help to seal the bank, keeping coins in.
Needle nose pliers bend, twist, and cut the wire
I started with a general torso, to which I added legs that also help to form the hind and to join with the snout. Finally, spirals give the extremities dimension. Extra credit for getting all four hoofs touching the floor simultaneously.
Step 4: PIGSKIN
Use these rectangle sheets to cover the wire skeleton. Plan for tabs that bend around wires or that fit into slots on underlying sheets.
Shaping these segments is a bending of the brain that should be embraced rather than disliked. To prevent frustration, make templates out of newspaper. With intuition, trial, error, and modification, you'll find the right template to transfer to the aluminum sheet (with a marker--on the unprinted side). Cut the sheets with aviation snips.
I started from the jar/lid and worked up. The legs are basically cones.
Consider the weight of the coins as you position the tab-slot articulations. Cut the slots with a utility knife.
Don't forget the coin slot and the curly tail, a potential showstopper.