Dr. Alphonse Mephesto

Dr. Alphonse Mephesto is an eccentric geneticist and stereotypical mad scientist, as he lives and works at South Park Genetic Engineering Ranch. Whenever the people of South Park need something beyond the natural, they turn to him. He is the leader of the North American Marlon Brando Look-Alikes (the "other" NAMBLA). He tends to put more than one ass on different animals.

Genetic Experiments
Dr. Mephesto made many genetic animals such like, the four (later five) -assed monkey, a four-assed ostrich, a four-assed mongoose, a mouse/duck, a gorilla/mosquito, a rabbit/fish (this is fake because Cartman said the ears are tied on them), a four-assed frog, a seven-assed Galapagos Turtle, loads of pissed off turkeys and a mutant clone of Stan.

Parodies
The character is an extended reference to Marlon Brando's portrayal of Dr. Moreau in the 1996 film version of The Island of Dr. Moreau. Like Dr. Moreau, Dr. Mephesto creates strange creatures with his talents- however his creations are things like animals with multiple sets of buttocks. Mephesto believes it is for the good of the Earth, and that one-assed animals are useless and must be destroyed. He even goes as far as presenting a "seven-assed Galapagos Turtle" in an attempt to win a Nobel Prize, but loses to Randy Marsh's "Unified Theory of Fart Thing." He also performs experiments ranging from simple DNA tests to creating a genetic clone of Stan Marsh for his son's project and later a clone of the Muslim prophet Muhammad.

In addition to Brando as Moreau, Mephesto is based at least partially on former UCLA molecular biology professor, Roger Bohman. Both Trey Parker and Matt Stone visited his class based on a recommendation of a friend, and they have admitted to Roger Bohman's more than passing resemblance to Mephesto.

Appearance
He wears brown trousers and a yellow flowered Hawaiian shirt with an open collar, revealing chest hair. His face is winkled and he wears a brown hat over a bandana that covers his hair. He is usually seen walking with a cane, whose handle is shaped like a pair of buttocks. Mephesto's appearance was tweaked and cleaned up slightly in his most recent appearance in "201", including an updated collar, hat, and gray hair.

Family
Dr. Mephesto has two children, Terrance, who is in the fourth grade class with the main characters, and Kevin. Although Mephesto is shown to be Terrance's father, they are never seen together save for one episode and he is never shown with the other parents.

Kevin
Kevin is Dr. Mephesto's assistant and adoptive "son". He wears similar clothing to Mephesto. He is usually described by others as "That little monkey guy". He seems on first glance to be mute, but he is rumored to have a very sweet, golden voice. He mostly follows Mephesto around. His name is revealed in "Starvin' Marvin" when Chef asks Mephesto "What the hell is that thing supposed to be?"

Kevin's story is told in the song "Mephisto and Kevin" by Primus from Chef Aid: The South Park Album; he was apparently a failed attempt to create a perfect pop singer, a test tube baby created from Michael Jackson's sperm and the egg of an unspecified, musically talented female donor, brought to term inside the womb of a llama. It is also revealed Kevin is legally Dr. Mephesto's son.

He is seen in a crowd in "Freak Strike". Kevin is never heard speaking until the episode "201", in which he yelps in surprise when Cartman/Mitch Conner trick their way into Mephesto's lab. He can also be heard singing at the end of "Mephisto and Kevin".

Brother
His brother has never been seen, but it was first said in the episode "Cartman's Mom is Still a Dirty Slut" that he attempts to shoot Mephesto every month on routine. Later in "201" it is revealed the real reason that he shot Mephesto is that he was a Broncos fan, and revealing that Cartman's biological father played for the Broncos may distract the team, which was having a good year.

Trivia

 * Dr. Mephesto is likely a Buddhist as in "An Elephant Makes Love to a Pig" he says "Oh, thank Buddha I found you boys!"
 * "Cartman Joins NAMBLA" (Season 4) was Dr. Mephesto's last speaking role until Season 14, in the episode "201". He was downgraded to an occasional background character until "201". Trey Parker later commented that by this point he and Matt Stone simply didn't find the character funny any more, and that they should have made him a member of the real NAMBLA to write him out permanently.
 * Dr. Mephisto seems to be based on Marlon Brando's character in the infamous bomb "The Island of Dr. Moreau", as he belongs to a Marlon Brando-look alike club, conducts genetic experiments, and has a small but deformed assistant.
 * Dr. Mephesto likely has an ass fetish, due to his experiments constantly having at least four asses.
 * In 201 it is revealed that Dr. Mephesto surgically alters his test subjects rather than genetically.
 * Dr. Mephesto walks with a cane, indicating he has some sort of limp. He may just carry it however as a fashion. The handle of the cane also seems to be shaped like a hairy ass, which is synonymous with his apparent fetish for asses.
 * Dr. Mephesto ways of surgery transformation on animals is the same as Dr Monroe from the book of his island
 * Dr. Mephesto is possibly not a fan of The Broncos as he was going to tell Cartman the truth about his father, which would have distracted the team.
 * Comedy Central has consistently spelled his name as 'Mephisto' in press materials, however Trey Parker's scripts including those for "An Elephant Makes Love to a Pig", "Cartman Joins NAMBLA" and "201" all spell the name as Mephesto, and the name is pronounced as such.
 * His name is a reference to Mephistopheles.

Prominence

 * "An Elephant Makes Love to a Pig" - Mephesto's first appearance. He rejects Kyle Broflovski's idea of splicing the DNA of a pig and an elephant. Later, he helps his son to make a clone of Stan.
 * "Starvin' Marvin" - Mephesto creates genetically modified turkeys, but they go crazy and put the whole town in danger.
 * "Cartman's Mom is a Dirty Slut" - Mephesto offers to help Cartman find out who his father is, but only for a price.
 * "Cartman's Mom is Still a Dirty Slut" - Mephesto gets shot by his brother right before he can reveal the identity of Cartman's father.
 * "Prehistoric Ice Man " - Helps unfreeze and talk to the prehistoric ice man.
 * South Park: Bigger, Longer & Uncut - Seen in the crowd singing Mountain Town (Reprise) at the end of the movie.
 * "Spontaneous Combustion" - Mephesto tries to win the Nobel Prize with a "seven-assed Galapagos Turtle", but loses to Randy. Later, he reveals that Randy's theory about Spontaneous Combustion is causing a change in the environment.
 * "Jakovasaurs" - Mephesto helps the Jakovosaur to reproduce.
 * "Hooked on Monkey Fonics" - Seen during the spelling bee.
 * "Are You There God? It's Me, Jesus" - Gives hormone pills to Stan.
 * "Cartman Joins NAMBLA" - Suggests Cartman joins NAMBLA but Cartman joins the 'North American Man Boy Love Association.' instead of the 'North American Marlon Brando Look-Alikes' which is what he really means. Is the spokesperson of 'the other NAMBLA' and helps the police catch the pedophile NAMBLA.
 * "Freak Strike" - Kevin cameos during the freaks song.
 * "Red Sleigh Down" - Cameo in crowd.
 * "I'm a Little Bit Country" - Cameo during the final song.
 * "It's Christmas in Canada" - Cameo in crowd at 04:58.
 * "Goobacks" - Kevin has a cameo during the final song.
 * "Britney's New Look" - Seen from the side leaving and entering the crowds to take photos of Britney Spears.
 * "Eat, Pray, Queef" - He appears as one of the men singing "Queef Free".
 * "201"- Cartman and Mitch Conner ask him who Cartman's real dad is, and Stan, Kyle, and Kenny ask him to clone Muhammad.
 * "The City Part of Town" - Cameo during the final scene in the newly opened South Park Whole Foods Market.