Where does “тигръ” come from?

тигръ (Old East Slavic) comes from Ancient Greek Τίγρις, from Old Persian 𐎫𐎡𐎥𐎼𐎠, from Akkadian 𒀀𒇉𒈦𒄘𒃼, from Sumerian 𒀀𒇉𒈦𒄘𒃼 — as fast as an arrow.