Ostara:

Old English Ēostre (also Ēastre) and Old High German Ôstarâ are the names of a putative Germanic goddess whose Anglo-Saxon month, Ēostur-monath, has given its name to the Christian festival of Easter. Eostre is attested only by Bede, in his 8th century work De temporum ratione, where he states that Ēostur-monath was the equivalent to the month of April, and that feasts held in her honor during Ēostur-monath had died out by the time of his writing, replaced by the "Paschal month." The possibility of a Common Germanic goddess called *Austrōn-, reflecting the name of the Proto-Indo-European goddess of the dawn, was examined in detail in 19th century Germanic philology, by Jacob Grimm and others, without coming to a definite conclusion.

Subsequently scholars have discussed whether or not Eostra is an invention of Bede's, and produced theories connecting Eostra with records of Germanic Easter customs (including hares and eggs).