Tonight, Tonight: Part 1 is the fourth episode of ALF's third season. It originally aired on Oct. 24, 1988.
ALF guests hosts the Tonight Show. This two-part episode (originally an hour-long special) is unique in that the events are separate from the story arc of the ALF TV series. In it, ALF is treated as if he is an actor in his own show rather than playing the character and storyline of the TV series.
"Tonight" is a song from the musical West Side Story, the chorus of which begins "Tonight, Tonight..."