William Blake compares the tiger's creator to a blacksmith. In the poem, he wonders about what kind of anvil and furnace would have been needed to create the tiger, as well as who wielded them. The "forging" of the fearsome creature is doused in mystery, as Blake ponders on where the tiger's fiery eyes could have come from, and who could have handled that fire. He thinks about who could have been skilled enough to craft and "twist the sinews" of the tiger's heart.