The Goddess Ostara is most closely associated with a Hare – she is shown having the head and shoulders of a hare. The hare is particularly a symbol of fertility and abundance as in nature the hare is able to conceive even whilst pregnant! And over the centuries this hare symbol has become the Easter Bunny – who brings eggs to children on Easter morning, the Christian celebration.  
Also, for many goddesses in Paganism, the Hare is a symbol of the moon. This also links to modern Easter celebrations as Christian Easter is determined by the phases of the moon.