pickerel (n.)

"type of long, slender, voracious freshwater fish," early 14c., pik (mid-12c. in place names), probably short for pike-fish, a special use of pike (n.2) in reference to the fish's long, pointed jaw, and in part from French brochet "pike" (fish), from broche "a roasting spit." In Middle English, proverbial for health and vigor.