The ghosts of Pacman!
I think it's really interesting how each of them have their own personalities in the game. especially for such an old game to have such a great system.
for those who don't know about it,
Blinky (red) follows pacman, Inky (cyan) joins the game late and kinda moves towards blinky's direction when chasing pacman, Pinky (pink.. duhh) has an 'ambush' AI, and clyde is kinda dumb and can't make up his mind.