This is a great pattern for use leftovers yarn. Pattern is written flat, but can be easy adjust to knit around.
Materials (for one cat):#4 needles, no more than 25 g of DK weight yarn in main color, about 5g of pink yarn(split DK weight yarn on half, and it will be just perfect), black tread for mouth,2 tiny buttons or beads for eyes, stuffing, darling needle and your wild imagination.

errata: you would need #4 DPN for i-cord