Langton's Ant

2D Turing machine with simple set of rules but complex emergent behavior

Langton's ant is a two-dimensional Turing machine with a very simple set of rules but complex emergent behavior. It was invented by Chris Langton in 1986 and runs on a square lattice of black and white cells.[1] The universality of Langton's ant was proven in 2000.[2] The idea has been generalized in several different ways, such as turmites which add more colors and more states.
Source: https://en.wikipedia.org/wiki/Langton%27s_ant