Von Neumann Probe-concept art
A Von Neumann probe is a type of spacecraft with the ability to self replicate itself, using materials it finds in the environment; such as material from other spacecraft and metals found inside comets and asteroids.
In Mathematics[]
Von Neumann's universal constructor, almost thrice replicated.
In mathematics the idea of a self-replicating object has been realized numerous times in Conway's game of life, and in fact John Von Neumann designed such a self-replicating object in a variation of the game of life which involved 29 unique states instead of the simple two unique states for the normal variation (one for "dead" and the other for "alive", hence how the game of life got it's name).