This article examines the simile that compares Penelope to a lion in Odyssey 4.791-794. Because of its perceived incongruity, the simile has often been passed over even by scholars who study lion similes in Homer. Looking sideways to Iliadic lions and backwards to the Epic of Gilgamesh, I argue that the simile of Odyssey 4 plays a central role in the narrative. Penelope the lion evokes war and its consequences and suggests a kind of mourning that gives rise to the thirst for revenge, which, within the context of the Odyssey, creates the impetus for Odysseus' nostos and Penelope's revenge.