Mark Twain wrote a letter to his daughter Suzy, which he sent from Santa Claus. Take a look at the letter here.
A Letter From Santa Claus
My Dear Susy Clemens,
I have received and read all the letters which you and your little sister have written me... I can read your and your baby sister's jagged and fantastic marks without any trouble at all. But I had trouble with those letters which you dictated through your mother and the nurses, for I am a foreigner and cannot read English writing well. You will find that I made no mistakes about the things which you and the baby ordered in your own letters--I went down your chimney at midnight when you were asleep and delivered them all myself--and kissed both of you, too... But... there were... one or two small orders which I could not fill because we ran out of stock ...
There was a word or two in your mama's letter which . . .I took to be "a trunk full of doll's clothes." Is that it? I will call at your kitchen door about nine o'clock this morning to inquire. But I must not see anybody and I must not speak to anybody but you. When the kitchen doorbell rings, George must be blindfolded and sent to the door. You must tell George he must walk on tiptoe and not speak--otherwise he will die someday. Then you must go up to the nursery and stand on a chair or the nurse's bed and put your ear to the speaking tube that leads down to the kitchen and when I whistle through it you must speak in the tube and say, "Welcome, Santa Claus!" Then I will ask whether it was a trunk you ordered or not. If you say it was, I shall ask you what color you want the trunk to be . . . and then you must tell me every single thing in detail which you want the trunk to contain. Then when I say "Good-by and a merry Christmas to my little Susy Clemens," you must say "Good-by, good old Santa Claus, I thank you very much." Then you must go down into the library and make George close all the doors that open into the main hall, and everybody must keep still for a little while. I will go to the moon and get those things and in a few minutes I will come down the chimney that belongs to the fireplace that is in the hall--if it is a trunk you want--because I couldn't get such a thing as a trunk down the nursery chimney, you know . . . .If I should leave any snow in the hall, you must tell George to sweep it into the fireplace, for I haven't time to do such things. George must not use a broom, but a rag--else he will die someday . . . . If my boot should leave a stain on the marble, George must not holystone it away. Leave it there always in memory of my visit; and whenever you look at it or show it to anybody you must let it remind you to be a good little girl. Whenever you are naughty and someone points to that mark which your good old Santa Claus's boot made on the marble, what will you say, little sweetheart?
Good-by for a few minutes, till I come down to the world and ring the kitchen doorbell.
Your loving Santa Claus
Whom people sometimes call
"The Man in the Moon"