The Jargon File (version 4.4.7, 29 Dec 2003):

wabbit
 /wab'it/, n.

    [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 a hack
    called RABBITS reported from 1969 on a Burroughs 5500 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.


The Free On-line Dictionary of Computing (30 December 2018):

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]