After the fight, Rum Tum Tugger calls upon the magician Mr. Mistoffelees for help ("Magical Mr. Mistoffelees"). Known as the "original conjuring cat", Mr. Mistoffelees can perform feats of magic that no other cat can do. He displays his magical powers in a dance solo and uses them to restore the lights and bring back Old Deuteronomy. Now, the Jellicle Choice can be made.
Cats introduced a marketing strategy that set the template for subsequent megamusicals. Early advertisements for the musical did not feature traditional pull quotes (despite many positive reviews) or any of the cast, focusing instead on branding the show itself as the star. It did this by adopting — and then aggressively promoting — a single recognisable image (the cat's-eyes logo) as the face of the show. The cat's-eyes logo was the first globally marketed logo in musical theatre history, and was paired with a tagline ("now and forever") to create what The Daily Telegraph called "one of musical theatre's greatest posters". Such branding emblems proved equally effective for later megamusicals, as seen with the waif Cosette for Les Misérables and the Phantom's mask for The Phantom of the Opera. This advertising method had the additional effect of diminishing the importance of critical reviews, popularising the so-called "critic-proof" status of megamusicals.
Cats are unusually dependent on a constant supply of the amino acid arginine, and a diet lacking arginine causes marked weight loss and can be rapidly fatal. Arginine is an essential additive in cat food because cats have low levels of the enzymes aminotransferase and pyrroline-5-carboxylate which are responsible for the synthesis of ornithine and citrulline in the small intestine. Citrulline would typically go on to the kidneys to make arginine, but because cats have a deficiency in the enzymes that make it, citrulline is not produced in adequate quantities to make arginine. Arginine is essential in the urea cycle in order to convert the toxic component ammonia into urea that can then be excreted in the urine. Because of its essential role, deficiency in arginine results in a buildup of toxic ammonia and leads to hyperammonemia. The symptoms of hyperammonemia include lethargy, vomiting, ataxia, hyperesthesia and can be serious enough to induce death and coma in a matter of days if a cat is being fed an arginine-free diet. The quick onset of these symptoms is due to the fact that diets devoid in arginine will typically still contain all of the other amino acids, which will continue to be catabolized by the body, producing mass amounts of ammonia that very quickly build up with no way of being excreted.
Serious damage is rare, as the fights are usually short in duration, with the loser running away with little more than a few scratches to the face and ears. However, fights for mating rights are typically more severe and injuries may include deep puncture wounds and lacerations. Normally, serious injuries from fighting are limited to infections of scratches and bites, though these can occasionally kill cats if untreated. In addition, bites are probably the main route of transmission of feline immunodeficiency virus. Sexually active males are usually involved in many fights during their lives, and often have decidedly battered faces with obvious scars and cuts to their ears and nose.
The domestic cat's ability to thrive in almost any terrestrial habitat has led to its designation as one of the world's most invasive species. As it is little altered from the wildcat, it can readily interbreed with the wildcat. This hybridization poses a danger to the genetic distinctiveness of some wildcat populations, particularly in Scotland and Hungary and possibly also the Iberian Peninsula.
Back in the present, after Gus exits, Skimbleshanks is seen sleeping in the corner ("Skimbleshanks: The Railway Cat"). He is the cat who is unofficially in charge of the night train to Glasgow. Skimbleshanks is considered vital to the rail operations, as without him "the train can't start". Within his song, a whole steam train engine is assembled out of objects in the junkyard.
"Memory" is the standout hit song from Cats. By 2002, the song had been played over two million times on radio and television stations in the US. It was the most requested song at piano bars and lounges in the 1980s, and was an equally popular choice at weddings, concerts and other gatherings. As of 2006, the song had been recorded around 600 times by artists such as Barbra Streisand, Barry Manilow, Judy Collins, and Johnny Mathis, in covers ranging from easy listening to techno. According to Sternfeld, it is "by some estimations the most successful song ever from a musical."
An alternative word is English puss (extended as pussy and pussycat). Attested only from the 16th century, it may have been introduced from Dutch poes or from Low German puuskatte, related to Swedish kattepus, or Norwegian pus, pusekatt. Similar forms exist in Lithuanian puižė and Irish puisín or puiscín. The etymology of this word is unknown, but it may have simply arisen from a sound used to attract a cat.