Iliad 5.639

In the Iliad, Hēraklēs as the only hero besides Achilles who qualifies as thūmoleōn ‘having the heart [thūmos] of a lion’; Achilles is thūmoleōn at I.07.228. In the Odyssey, Hēraklēs is the only hero besides Odysseus who qualifies as thūmoleōn ‘having the heart [thūmos] of a lion’, at O.11.267; Odysseus is thūmoleōn at O.04.724 and O.04.814.