Free printable masks: to create the masks, simply print on card stock and laminate. Cut around the outside of the head, cut the eye holes (I use a box cutter), poke one hole near each ear and thread a piece of string or elastic through to create a mask.
One of our themes for the summer is farm animals and the sounds they make. We put together this cute set of materials to use in conjunction with Old McDonald Had a Farm. (It also is a perfect companion to the Peek-A-Boo Farm app available on iTunes.