Click Clack Moo: Cows that Type is a story about cows owned by Farmer Brown. These cows type and post memos or letters to Farmer Brown about their demands/requests for different things. The cows type on behalf of other animals in the barn as well.
This book lends itself well to talk about writing a letter to someone and the specific parts of a letter (heading, greeting, body, closing, and signature). I would allow my students to write a letter to a relative or friend for this activity. There is a song about the parts of a letter (set to the tune of "The Addams Family") that I would use as a memory aid for students, adding movements or snaps with the song. Before having them write their own letters, I would do an example with class input then, or we would have been preparing by writing letters as a class.
Lexile Level - AD160
(AD: Adult Directed, a book typically read to students)