This episode tests Zoidberg's competency as a doctor (it's shown that he's a fine doctor for aliens, just not for humans or robots).
This episode reveals that Mom's real name is Carol.
The song that plays when Zoidberg tries to kill the Professor is Mr. Sandman.
The Tip of the Iceberg
The title of this episode is a reference to the saying: "the tip of the iceberg".
Rube Goldberg machines
The elaborate killing machine the Planet Express crew made to kill the professor is a reference to Rube Goldberg machines
When Fry got sick he looked like different four different cartoon characters:
A Simpsons character, in which he said Bart Simpson's catchphrase,"Ay Carumba!"
Garfield, in which he said Garfield's catchphrase, "I hate Mondays."
Kermit the Frog, in which he said, "It's not easy being gangrenous", as opposed to Kermit's catchphrase "It's not easy bein' green".
Superman and Little Caesar's
Zoidberg blurts "Great Little Ceasar's ghost!", which refrences Superman's catchphrase "Great Caesar's ghost!", and the pizza resturant chain, Little Caesar's
Bender says to the proffesor "What' choo talkin' bout, Proffesor?". This is a play on the catchphrase of Arnold Jackson from the television sitcom from the late '70s, called Diff'rent Strokes, which he says to his brother, Willis, "What' choo talkin' bout, Willis?"
The Three Stooges
Mom says to her sons to "stooge" out of her office. This is a reference to the Three Stooges.
The Tritonian Yeti's apperance and poisonous nature is simalar to Mugato from the Star Trek episode "A Private Little War".