Who Is Cartman's Father In South Park?

South Park is an animated American television comedy series that was created by Trey Parker and Matt Stone. It has been on air since 1997. Eric Cartman is the main character of the series, who is often in conflict with other kids. He does not have a father and is raised by his single mother Liane Cartman who is known for her bad character in the community.

Cartman's father is in fact (the person we know from the show as) his mother.
Per the following Wikipedia link (en.wikipedia.org
"Cartman's Mom is a Dirty Slvt" - In this episode it is revealed that she has slept with almost every adult in South Park (except Halfy who has no legs), including Chef, Mr. Garrison, Principal Victoria, Father Maxi, Dr. Mephisto, Jimbo Kern, Gerald Broflovski, Jesus, and the 1989/1991 Denver Broncos. She also explains sex to Cartman as "sometimes the man puts his hoo-hoo-dilly in the woman's cha-cha".
"Cartman's Mom is Still a Dirty Slvt" - This episode reveals that Ms. Cartman was her son's father; thus, she is an intersexual (called a hermaphrodite on the show).
We just don't know who his mother is other than it is someone that his 'mother' (i.e. Father) knocked up because after all these revelations Cartman gives up.