shark bait

From shark + bait.

• "Holden's heart was loud enough to deafen him. He couldn't go against a mage of the power. No one could, no one could ever survive. One word and he was shark-bait."
• "I usually tried to cheer Pete up; this time he was dragging me down with him into his bottomless depths of despair. I simply could not accept the general newsroom consensus that Ryan was shark bait."

• dead duck
• sitting duck