The traffic light is a common formation of four blinkers and is the most common member of the familiar fours, also being the only one made from oscillators. A common predecessor is the T-tetromino. Although it behaves the same in some important non-standard rules such as HighLife as it does in standard Life, it does not appear nearly as frequently in many of those rules due to its common predecessors being unstable.
Drawing a single cell in the middle of the traffic light while it is in its "+" phase will eat the whole traffic light, leaving nothing behind. Drawing a cell a knight's move away in the other ("O") phase results in a clean fishhook instead.