Abstract: A nipper tool to remove a peripheral portion of the lip of a bivalve mollusk shell, and especially the shell of an oyster, to aid opening with a shucking knife provides a peripherally defined angulated handle structurally interconnecting a peripherally defined cylindrical nipping body. The nipping body defines an insertion notch in its lower forward portion distal from the handle to provide access to the nipping body chamber which slidably carries a nipper plunger with depending nipper blade to nip the lip of an oyster in the insertion notch. The nipper plunger is biased downwardly in the nipper body chamber by a compression spring and movable against this bias by a bell crank extending into the handle structure. A first manually operated species provides a pivotally movable lever adjacent the handle, with linkage to the bell crank to move the nipper plunger against its bias and release it to nip an oyster shell lip.