Source : Webster's Revised Unabridged Dictionary (1913)

Sleepyhead \Sleep"y*head`\, n.
   1. A sleepy person.

            To bed, to bed, says Sleepyhead.      --Mother
                                                  Goose.

   2. (Zo["o]l.) The ruddy duck.

Source : WordNet®

sleepyhead
     n : a sleepy person