To wish someone death whilst they are sitting on the toilet; most likely in some excruciatingly painful anal explosion that involves blood and feces thrown everywhere. DIE ON THE TOLIET.
Asshole Friend: Hey Dude, so your hittin that aren't you!
Dude: You know what Asshole, Die On The Toilet! (D.O.T.T.)
Asshole Friend: I just might, I just might!