Cardboard Boxes

• Different sizes of cardboard boxes are perfect for creating monster costumes. Open both ends of a large cardboard box to create a basic body and help children cut a hole on each side so they can push their arms through. Cut eye holes and a mouth space in a smaller box so the children can wear it over their heads. Tape the two together using masking tape, or keep them separate for ease of getting them on and off. Kids can either paint the monster boxes or apply papier mache to create more interesting shapes.
  
  

Papier Mache

• Papier mache is an excellent medium for creating lumps and bumps and strange monster body shapes. Use a cardboard box as a basic mold. Children should rip newspapers into strips, soak them in craft glue, then layer them onto their boxes, building up different shapes. If they want to add larger shapes to their costume, they should cut the shapes from another cardboard box, tape them on with masking tape, then layer papier mache over that. Let the papier mache dry overnight after every three or four layers, to prevent it from becoming soggy and taking too long to dry.
  
  

Decorating

• Craft paints are available in a wide range of colors for children to decorate their monsters. Provide children with gruesome colors such as neon green and black for a traditional monster look. Scrunched-up tissue paper can be glued onto the body -- either onto dried papier mache or straight onto the box -- to create monster skin. Painting on bubble wrap, then gluing it onto the body, will produce a textured "scale" effect.
  
  

Legs

• Old tights can be painted with craft paints to create monster legs. Have children paint them in monster colors and glue on scraps of felt and wool to create hideous hairy legs. Have them cut long "toenails" from old plastic bottles and glue these onto the feet of their tights to create monster claws. To add extra legs, have them cut the tights apart into two legs, stuff the legs with newspaper, and paint and decorate them as they did for the tights they will wear. Tie a knot in the open ends of the legs and glue or tape them onto the side of their monster bodies.