Source : Free On-Line Dictionary of Computing

wabbit
     
        /wab'it/ [almost certainly from Elmer Fudd's immortal line
        "You wascawwy wabbit!"]  1. A legendary early hack reported on
        a System/360 at RPI and elsewhere around 1978; this may have
        descended (if only by inspiration) from hack called RABBITS
        reported from 1969 on a Burroughs 55000 at the University of
        Washington Computer Center.  The program would make two copies
        of itself every time it was run, eventually crashing the
        system.
     
        2. By extension, any hack that includes infinite
        self-replication but is not a {virus} or {worm}.  See {fork
        bomb} and {rabbit job}, see also {cookie monster}.
     
        [{Jargon File}]