Banana, stabbing a seal with a:

Banana, stabbing a seal with a: 1. Using a tropical crescent-shaped fruit to terminate the life of an aquatic mammal of the phocidae or otaridae families. 2. Hopelessly equipped for the job; using entirely the wrong tool to get something done; repeatedly using the same technique again and again hoping in vain for a different result; too dim to change tactics. (see Bark into the wind, up the wrong tree; Grasping at fog; Nailing a jelly to the wall, trying to)