"Io mangio un orso."
Il signore Google says no.
Whoopsy.. I thought she asked if this specific phrase is the Italian equivalent of "I could eat a horse". :P
Anyways.. from what I've found, there is a phrase "mi mangerei un cavallo" (I could eat a horse), but the more common variant is "mi mangerei un bue" (I could eat an ox). Even "mangerei un orso" (I could eat a bear) is sometimes used. but rarely. :)