A T-Block is a tetromino shaped like the letter "T", and is the second main protagonist of the game. It is a highly adaptable tetromino, which can be used to even out a variety of stacked shapes. In many Tetris games, it is the only piece when doing a twist will earn the player bonus points for doing so. Although in most games it can only clear up to two lines at once, all games that use SRS can allow a T-Block to rotate and wall kick in very unusual ways, enabling the player to create the T-Spin Triple(s)/Back to Back T-Spin Triple(s).
It is also the Tetris logo. However, the Tetris logo is not split into 4 minoes.
In Puyo Puyo Tetris, the character Tee is based off of the T-Block shape. It has references to T-Spins.
Since Tetris Worlds in 2001, the T-Block has been colored purple.