In cellular automata, a replicator is a pattern that produces copies of itself.
In the one-dimensional Rule 90 cellular automaton, every pattern is a replicator. The same is true in the life-like cellular automaton rule Replicator (B1357/S1357).[1] [2]
Highlife (B36/S23) rule has a simple replicator.[1]
On November 23, 2013, Dave Greene built the first replicator in Conway's Game of Life (B3/S23).[3]