“South Park,” the Comedy Central series, is an animated show that tries its best to push buttons and the boundaries of free speech by mocking every high-profile target in sight, from Hollywood celebrities to religious figures. But its creators may have gotten more than they bargained for with two recent episodes that satirized the Prophet Muhammad  one that elicited an ominous message from an Islamic group based in New York, and one that was censored by the cable network that shows it.

On April 14 Comedy Central broadcast the 200th episode of “South Park,” a cartoon that Trey Parker and Matt Stone have produced for that channel since 1997. In honor of the occasion, Mr. Parker and Mr. Stone populated the episode with nearly all the famous people their show has lampooned in its history, including celebrities like Tom Cruise and Barbra Streisand, as well as major religious figures, like Moses, Jesus and Buddha.

Cognizant that Islam forbids the depiction of its holiest prophet, Mr. Stone and Mr. Parker showed their “South Park” characters agonizing over how to bring Muhammad to their fictional Colorado town. At first the character said to be Muhammad is confined to a U-Haul trailer, and is heard speaking but is not shown. Later in the episode the character is let out of the trailer, dressed in a bear costume.

The next day the “South Park” episode was criticized by the group Revolution Muslim in a post at its Web site, revolutionmuslim.com. The post, written by a member named Abu Talhah Al-Amrikee, said the episode “outright insulted” the prophet, adding: “We have to warn Matt and Trey that what they are doing is stupid, and they will probably wind up like Theo van Gogh for airing this show. This is not a threat, but a warning of the reality of what will likely happen to them.”