An Etymological Dictionary of the German Language/Krebs
Krebs, m., ‘crayfish,’ from the equiv. MidHG. krëbeȥe, krëbeȥ, OHG. chrëbiȥ, chrëbaȥo, m.; comp. Du. kreeft, m., ‘crayfish’; allied to LG. Krabbe. The G. word passed at an early period into Rom. (comp. Fr. écrevisse, ‘cray fish,’ and crevette, ‘shrimp’). It is not connected with Gr. κάραβος, but rather with OHG. chrâpfo, ‘hook’; Krebs, lit. ‘hooked or claw fish’?. See Krapfen (2).