Related:

• He thought he saw an Elephant, That practiced on a fife
  He looked again, and found it was A letter from his wife....
• He thought he saw a Rattlesnake That questioned him in Greek, He looked again and found it was The Middle of Next Week.
  'The one thing I regret,' he said, 'Is that it cannot speak!...
• He thought he saw a Buffalo Upon the chimney-piece
  He looked again, and found it was His sister's husband's niece....
• Yes, let's consider," said Bruno, putting his thumb into his mouth again, and sitting down upon a dead mouse.
  "What do you keep that mouse for?" I said. "You should either bury it or else throw it into the brook....
• He thought he saw an albatross That fluttered 'round the lamp.
  He looked again and saw it was A penny postage stamp....
• I'm sure nobody walks much faster than I do! He can't do that, said the King, or else he'd have been here first.
  -- Lewis Carroll...