T-tetromino is one of 5 tetrominoes. It is a common predecessor of the traffic light, and when paired with another T-tetromino it can become a predecessor of the pulsar.
In a cylindrical grid with a width of 6, the T-tetromino is always a replicator. It copies itself on the 15th and 40th generations of every 40 generations. However, because it leaves behind blocks, blinkers, and sparks, it does cleanly replicate itself until after 200 generations. It acts much the same way as the replicator in Highlife because the two copies of the T-tetromino appear offset in opposite directions of the original. Also, two replicators will destroy each other if they are next to each other. The T-tetromino replicates orthogonally and 35 cells away from the original.
In the non-totalistic Life-like cellular automaton tlife, the T-tetromino is an extremely common c/5 orthogonal spaceship.