http://en.wikipedia.org/wiki/Easter_Bunny
Story behind the easter bunny laying eggs.
The idea of an egg-laying rabbit came to the United States in the 18th century. German immigrants in the Pennsylvania Dutch area told their children about the "Osterhase". "Hase" means "hare", not rabbit, and in Northwest European folklore the "Easter Bunny" indeed is a hare, not a rabbit.
Only good children received gifts of colored eggs in the nests that they made in their caps and bonnets before Easter. Presumably, the "Oschter Haws" laid them when the children were not looking.
A hundred years later Jakob Grimm wrote of long-standing similar myths in Germany itself. Noting many related landmarks and customs, Grimm suggested that these derived from legends of Ostara.