Making action figures takes some preparation, but once you master the basics you can produce your own figures to your specifications. The basic supplies are a modelling material such as Sculpey polymer clay, with wire and aluminium foil to support the structure. If you plan to articulate your figure, the easiest option is to use bendable Sculpey over wire. For a jointed figure you may need to use more exotic materials such as neodymium magnets.
Remove the action figure from the bubble pack (if you are using one) without damaging the pack. Measure the dimensions of the pack and the toy.
Sketch your own figure, noting dimensions such as height. Decide whether it will be posable and if so whether it will use bendable wire, elastic or magnets. Sketch all the elements with notes on dimensions and connections. Sketch where any elastic cords will go.
Build armatures from wire. Wrap foil around the wire to build up the shape. If you are using bendable Sculpey, wrap the armatures in foil and include them where the figure will bend. Make any eyelets for elastic joints from wire.
Clean and powder your work surface, hands and tools. Condition (knead and soften) the neutral Sculpey. Build up basic shapes, omitting small details such as fingers (and joints if you are using bendable Sculpey). If you are using elastic, bore holes for it with a toothpick or skewer. If you are using magnets and grub screws (short fat screws) embed them in the Sculpey or form it around them, leaving a cup of Sculpey above each screw to hold the magnet.
Bake according to the instructions. Allow to cool. Condition and mix coloured clay or bendable Sculpey. Build up surfaces and details on your figure. Sculpt small details using toothpicks. Bake again. Add acrylic paint details when cool. Varnish when dry (paint and varnish make flake on bendable figures).
Assemble the figure. Run elastic cord through the bore holes and wire eyelets, pull very tight and tie in loops. Clip the magnets into the sockets.
Make an image and stick it to your pack or paint it with acrylics. Place the figure in the pack. Seal with rubber cement so the bubble can come off without damaging the card.
Neodymium magnets can smash together with dangerous force. They can interfere with pacemakers and can kill if swallowed. They can also wipe magnetic media and damage computer equipment. Observe the safety precautions recommended by the vendor.