Isaiah 40:31: those who wait upon the LORD will mount up with wings like what?

Answer: Eagles

They "will renew their strength; they will mount up with wings like eagles; they will run and not grow weary."

“But those who wait upon the LORD will renew their strength; they will mount up with wings like eagles; they will run and not grow weary, they will walk and not faint.”— Isaiah 40:31 (BSB)