This Feed the Letter Alphabet Center Game set includes nine different themes, each with two size options. I would suggest printing on cardstock and laminating for longevity. Once you print out the big image for the set you chose to use, cut out the mouth. Attach the open mouth image to an empty tissue box, small trash can, anything that has an opening, and have students feed the object with the letter. Students can say the letter, sound, or both. This would also make a great activity for small group or whole group lessons.
Please let me know if you have any questions. Happy teaching!