There is no definitive historical evidence that a goddess named Eostre and her hare companion was part of pagan folklore
Adrian Bott
Saturday 23 April 2011 10.00 EDT
... The colourful myths of Eostre and her hare companion, who in some versions is a bird transformed into an egg-laying rabbit, aren't historically pagan. They are modern fabrications, cludged together in an unresearched assumption of pagan precedence. Only one piece of documentary evidence for Eostre exists: a passing mention in Bede's The Reckoning of Time. Bede explains that the lunar month of Eosturmonath "was once called after a goddess... named Eostre, in whose honour feasts were celebrated." However, even this may only have been supposition on Bede's part ...
http://www.theguardian.com/commentisfree/belief/2011/apr/23/easter-pagan-roots
Eostre - Spring Goddess or NeoPagan Fancy?
By Patti Wigington
Updated January 27, 2015.
... Eostre first makes her appearance in literature about thirteen hundred years ago in the Venerable Bede's Temporum Ratione. Bede tells us that April is known as Eostremonth, and is named for a goddess that the Anglo-Saxons honored in the spring. He says: "Eosturmonath has a name which is now translated 'Paschal month', and which was once called after a goddess of theirs named Eostre, in whose honor feasts were celebrated in that month." After that, there's not a lot of information about her, until Jacob Grimm and his brother came along in the 1800s. Jacob said that he found evidence of her existence in the oral traditions of certain parts of Germany, but there's really no written proof. Interestingly, Eostre doesn't appear anywhere in Germanic mythology, and despite assertions that she might be a Norse deity, she doesn't show up in the poetic or prose Eddas either ...
http://paganwiccan.about.com/od/ostarathespringequinox/qt/Eostre.htm
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