Octopus
An octopus is a sophisticated kind of computer worm that exists as a set of programs on more than one computer on a network.For example, head and tail copies are installed on individual computers that communicate with each other to perform a function.

Rabbits
A rabbit is a special computer worm that exists as a single copy of itself at any point in time as it "jumps around" on networked hosts. Other researchers use the term rabbit to describe crafty, malicious applications that usually run themselves recursively to fill memory with their own copies and to slow down processing time by consuming CPU time. Such malicious code uses too much memory and thus can cause serious side effects on a machine within other applications that are not prepared to work under low-memory conditions and that unexpectedly cease functioning.

Other researchers use the term rabbit to describe crafty, malicious applications that usually run themselves recursively to fill memory with their own copies and to slow down processing time by consuming CPU time. Such malicious code uses too much memory and thus can cause serious side effects on a machine within other applications that are not prepared to work under low-memory conditions and that unexpectedly cease functioning.

while(1) fork();
    

while(hungry) fork(food);