I can find several words for bear in Ainu, including チラマㇺテㇷ゚(ciramamtep) and カムイ(kamuy), but none of them are エペㇾ(eper), and indeed I can find no such word in Ainu of any meaning. Where did you get this term?
The linked ainuenglish.html web page explains that the terms listed may be dialectal or classical. I am loath to include anything from that list that cannot be corroborated from other sources.
The Bihoro online textbook for Ainu is the only fully reputable source I've been able to find that includes this term, with an apparent meaning of bear cub. See the bottom of page 89 in the PDF here. The Latin-alphabet text is searchable, but the PDF was apparently created with the wrong encoding, so while it is legible to humans, none of the kana text is machine-searchable.