The Tip of the Zoidberg

The crew uncovers a dark secret concerning a covert mission undertaken by the Professor and Dr. Zoidberg many years earlier.

Act I: "We still have three or four coworkers with plenty of spare parts."
Frustrated with Zoidberg's incompetence as a doctor, the Planet Express crew demand Professor Farnsworth to fire him. The professor refuses, and the crew question why Zoidberg was ever employed in the first place. A series of flashbacks reveal that Zoidberg first met and befriended Farnsworth in 2927, during a mission to kill a Tritonian yeti for Mom. During the mission, Farnsworth became susceptible to hypermalaria, a fatal, incurable disease which can either strike instantly or remain dormant for years. As a favour to Farnsworth for killing the yeti and saving his life, Zoidberg agrees to an arrangement: when Farnsworth begins to experience symptoms of the disease, Zoidberg will perform a mercy killing before the disease can fully manifest. As a result, Zoidberg was employed by the professor for the purpose of carrying out the task.

Act II: "Your mistake is being Humans!"
In the present, the professor begins to experience the symptoms of hypermalaria, and insists that Zoidberg must kill him by surprise. The crew catch Zoidberg attempting to murder the Professor, and restrain him with the professor's lab coat and imprison him. Zoidberg notices a single white hair on the professor's coat and deduces that he does not have hypermalaria. Rather, he has contracted yetiism after being scratched by the Tritonian yeti. The illness mimics the symptoms of hypermalaria, but results in its victims transforming into a yeti.

Act III: "Also, the salad's ready."
Zoidberg escapes and goes to Mom, exchanging a coupon for a free tanning session for the yeti's head so that he may use its pineal gland as an antidote. Meanwhile, the professor reveals the truth to the crew, who decide to kill him themselves, using an elaborate mechanical killing machine. Zoidberg returns to announce his discovery to the crew, just as the professor begins transforming into a yeti. Zoidberg forces him to swallow the yeti gland, successfully curing him. As the crew goes to a tanning salon to celebrate, Zoidberg laments giving away his coupon. A grateful Farnsworth offers to treat Zoidberg to a free session, and they both depart as friends.

Production
While originally known as "Nine-tenths of a Zoidberg is Underwater", the episode title changed in the process.

During June 2011, Countdown to Futurama released two items of promotional material for the episode: concept art of Triton Base Camp on 3 June and part of the storyboard showing a young Professor Farnsworth and Zoidberg on a Yeti-hunting trip on 4 June.

On 12 August, Comedy Central released a video clip featuring Zoidberg performing surgery on Fry, Leela, and Hermes.

Reception
In its original U.S. airing on 18 August, 2011, the episode scored a 0.7 share among adults aged 18-49, and 1.382 million total viewers. This is down about 80,000 viewers from the previous week's airing of "Fry Am the Egg Man".

Trivia

 * Mom's real name is revealed to be Carol.
 * This episode focuses on the relationship between Zoidberg and the Professor, who are shown to be good friends. This contradicts previous episodes, most notably "Teenage Mutant Leela's Hurdles", where the Professor's last words are, "I curse Zoidberg!" Of course, he may have been delirious (considering both the circumstances and the Professor's mentality).
 * This episode also jokes around with Zoidberg's medical competence; he is depicted as being (as usual) horrible with humans, but shows himself to be excellent with other alien races, most notably yetis. For example, Zoidberg is able to extract the Tritonian yeti's gland that will save the Professor's life in record time. Mom also says that Zoidberg is "the best there is if you need an alien hacked to pieces!... In the budget category."
 * This episode was originally titled "9/10ths of Zoidberg is Underwater".

Allusions

 * Zoidberg causes Fry to lose blood and develop a host of syndromes named after pop culture figures.
 * Fry first develops a condition called "Simpsons jaundice", referring to the yellow skin of characters from The Simpsons. He then says the phrase "", a catchphrase of.
 * Fry then gets "Garfield syndrome", a reference to the cat.  He looks like Garfield and even says his phrase "I hate Mondays".
 * Fry then develops "Muppet gangrene". This causes him to act like and say that "It's not easy being gangrenous", referring to Kermit's famous refrain from "". He is also only seen from the waist up, a reference to a long list of popular puppet characters.
 * Finally, Fry gets an unknown condition that makes him look like a.
 * Near the beginning of the episode, The Professor and Zoidberg are depicted as feeding mice to owls, similar to how in modern-day life, people will throw bread crumbs to pigeons.
 * In a flashback to a military field hospital on Triton, Professor Farnsworth asks, "How bad is it, doctor?" and Dr. Zoidberg responds, "Super bad," alluding to the popular film,, which premiered a few years before this episode was produced.
 * During Zoidberg's attempts at murdering the Professor, Chet Atkins' version of the song "" plays over the scene.
 * The Tritonian Yeti, including its poisonous nature, is designed like the of the Star Trek episode "."
 * Zoidberg exclaims, "Great Little Caesar's ghost!" a play on the catchphrase of  character, "Great Caesar's ghost!", and the chain of pizza restaurants.
 * The Murderlator is an example of a.
 * Mom's three sons are told to "Stooge out," a reference to the.
 * "Stooge out" could also refer to her sons being "stooges", e.g. devoted followers who are used by Mom for her own purposes.
 * After her sons leave, Mom says "John Zoidberg...it's been a long time. How've you been?".  While perhaps not intentional, this is very similar to the first lines said by  in the video game .  Both characters share a few traits including passive-aggressive behavior and a publicly genial image that hides malevolent motives. Also, Mom's real name is Carol, a short for "Caroline", GLaDOS former human identity.
 * When Fry uses the phrase "believable hulk", it's a reference to the double-meaning of the word "incredible".

Goofs

 * Methane is actually odorless. Since it is often mixed with other odorous compounds, people mistakenly assume that it smells bad.
 * It is possible that Zoidberg's species is capable of smelling methane.
 * When everyone grabs a vial of poison, a sixth gloved hand grabs a vial as well. In the next shot it is shown that this is Scruffy's hand, yet he isn't involved in the poisoning process.
 * Scruffy could have been kill check 6.
 * Scruffy is wearing gloves when he takes one of the vials of poison, but in the next shot when he commences the mercy killing, they're gone.
 * The vegetables in Bender's salad were cut with the blade from the death wheel after the poison had been dripped on it, yet the Professor is seen eating the salad at the end.
 * The poison was and is lethal in doses of 1.5mg per 1kg of body weight. A rough estimate would put only 1.4mg of cyanide on the blades when they cut the vegetables, so there wasn't enough for it to really affect the Professor unless he weighs less than 1kg/2.2lbs.
 * Actually with about 20 drops to the milliliter, and a specific gravity of 1.2 for cyanide solution, a drop would weigh around 0.06 grams so two drops would be 120 milligrams. Of course you could also argue that since there are six blades on the death wheel and only two of them were poisoned (assuming Hermes' and Fry's drop went on different wheels), there is a 4 in 6 chance that the blade that cut the vegetable wasn't poisoned although this number become smaller with each vegetable (assuming the previous one wasn't poisoned).
 * When the crew discover that Zoidberg had sand-crabbed his way out of his surgery, Amy looks out of the window and down to the street below, showing that his surgery is above the ground floor, but the hole he created is full of soil. If anything, the hole would just drop down to the floor below.
 * He could've fallen down to the floor below and sandcrabbed out again for the fun of it.
 * Mom seems rather surprised to see Zoidberg, but hasn't Mom seen Zoidberg with the Planet Express crew in the past?
 * The only other time when Mom and Zoidberg could have interacted was in "Future Stock" and even then they probably did not cross paths as he had sold his shares of PlanEx. Also in the past she may have mistaken him for another Decapodian.
 * They are seen interacting in "Three Hundred Big Boys" but Mom never indicates she doesn't recognise him, merely commenting on his "impression" of a poor person.
 * Yeti Farnsworth knocks the death wheel off-course, through Bender and off towards a wall, obliterating the Murdolator as it goes, but, when Farnsworth recovers underneath the wreckage, the death wheel is right on top of him.
 * When the Mururlator was collapsing, we didn't see where the death-wheel landed, so it could have landed on Farnsworth when the camera was on eveyone else.
 * Bender uses a lighter to light his cigar, but it's been established in several episodes that he has one built into his hand.
 * Perhaps his hand-lighter was out of fuel and he simply hadn't gotten around to replacing it.
 * After Zoidberg cuts Leela in half, both her tank top and pants are frayed, even though if he only cut her once this could only happen if her pants were attached to her tank top, and if she were cut at the precise place that the two met.

Continuity

 * The flashbacks reveal once again that people in the future do not age the same as people of the 21st century. In 2927, Professor Farnsworth would have been 85-86, yet appears youthful and is healthy enough for the rigors of military duty.
 * The tool Zoidberg uses to extract the Tritonian yeti's gland is the same one seen in "The Series Has Landed" when Zoidberg examines Fry.
 * Bender once again shows his love for cooking by making a salad before adding his drop of poison on the death wheel. It was established in "My Three Suns".
 * Fry once again mistakes an inanimate object for a living alien, having previously made out with what he thought was "the radiator woman from the radiator planet", in "The Lesser of Two Evils".
 * This episode establishes the fact that Zoidberg has been working for Planet Express for 80-some years. However, in "Insane in the Mainframe", the crew is celebrating Zoidberg's 10th year at the company.
 * The phrase "Great Caesar's ghost" was previously parodied on "Bender Should Not Be Allowed on Television" by Calculon as "Great Shatner's ghost!"
 * In The Beast with a Billion Backs, Zoidberg thinks that he is playing deathball for his freedom.
 * Dr. Zoidberg's door says "M"D. in "The Duh-Vinci Code" Zoidberg says that his doctorate is in art history.

Characters

 * Debut: Actual Doctor
 * Amy
 * Bender
 * Professor Farnsworth
 * Fry
 * Hattie McDoogal
 * Hermes
 * Igner
 * Larry
 * Leela
 * Mom
 * Scruffy
 * Walt
 * Debut: The Tritonian Yeti
 * Zoidberg