Question: Rocko's Modern Life is an American animated sitcom created by Joe Murray for Nickelodeon, the series centers on the surreal life of an anthropomorphic Australian-immigrant wallaby named Rocko as well as his friends: the gluttonous steer Heffer, Heffer Wolfe is a fictional character on the cartoon "Rocko's Modern Life" and the comic book series of the same name, who provided the voice of the anthropomorphic steer.?

Context paragraphs:
Camp Lazlo: Camp Lazlo (stylized as CAMP LAZLO!)  is an American animated television series created by Joe Murray and produced by Cartoon Network Studios.  The show revolves around Lazlo, a spider monkey who attends a Boy Scout-like summer camp with a cast of anthropomorphic animal characters.  The series has a style of humor similar to Murray's previous series, "Rocko's Modern Life".

Trash-O-Madness: Trash-O-Madness is a 1992 animated short (which began production in 1991).  Created by Joe Murray, who, prior to this point, had made several independent animated shorts (including "The Chore" and "My Dog Zero"), as well as several MTV IDs, it was the pilot episode for what became Nickelodeon's 4th nicktoon, "Rocko's Modern Life".  The series ran for 4 seasons and 52 episodes, from 1993 to 1996.  During the first season, a new version of the pilot, that was extended for the purposes of including it as a regular episode, was produced.  The new version was paired up "The Good, the Bad, and the Wallaby" as the 10th episode to be produced, and aired as the 6th.  In addition, that episode featured an extended end credit sequence to accommodate the names of production crew behind "Trash-O-Madness".  On February 7, 2012, the original pilot version found its way onto Shout!  Factory's season 2 DVD as a special feature.

Rocko's Modern Life: Spunky's Dangerous Day: Rocko's Modern Life: Spunky's Dangerous Day is a Super Nintendo Entertainment System video game released in the United States on April 1, 1994 and in 1997 in Canada, and is based on Joe Murray's "Rocko's Modern Life" television series on Nickelodeon.  It was developed by Viacom New Media.

Rocko's Modern Life: Static Cling: Rocko's Modern Life: Static Cling is an upcoming one-hour American animated television special based on Joe Murray's "Rocko's Modern Life" TV series.  The TV special is projected to premiere on Nickelodeon in 2018.

Filburt: Filburt Shellbach is a main and supporting character of the cartoon "Rocko's Modern Life" and the comic book series of the same name.  In the Australian website of the television show, his name is sometimes spelled as Filbert and sometimes as "Filburt".  In the comic book, his name is spelled "Filbert".  On the show's creator Joe Murray's website and in the episodes "Born to Spawn" and "Uniform Behavior", his name is spelled as "Filburt".  In the episodes "Born to Spawn" and "Fortune Cookie", he is referred to as Mr. Filburt Turtle.  However, in the episode "High Five of Doom" Rocko and Heffer read in Filburt's diary that his full name is Filburt Shellbach.  Doug Lawrence provided Filburt's voice.

Joe Murray (animator): Joseph David "Joe" Murray (born May 3, 1961) is an American animator, writer, illustrator, producer, director, and voice actor, best known as the creator of the Nickelodeon animated series "Rocko's Modern Life" and the Cartoon Network animated series "Camp Lazlo".  Born in San Jose, California, Murray was interested in a career in the arts when he was three.  He credits his high school art teacher Mark Briggs with teaching him a lot about art.  Murray was a political cartoonist for a newspaper, often targeting then-President Jimmy Carter.  As a young adult Murray was hired as a designer at an agency, where he invested his earnings from the production company into independent animated films.  In 1981 at age 20, he founded his independent illustration production company, Joe Murray Studios, while he was still in college.

Heffer Wolfe: Heffer Wolfe is a fictional character on the cartoon "Rocko's Modern Life" and the comic book series of the same name.  Tom Kenny provided the voice of the anthropomorphic steer.  His catchphrase, which can be heard in the series' opening credits, is "That was a hoot!"

Rocko's Modern Life: Rocko's Modern Life is an American animated sitcom created by Joe Murray for Nickelodeon.  The series centers on the surreal life of an anthropomorphic Australian-immigrant wallaby named Rocko as well as his friends: the gluttonous steer Heffer, the neurotic turtle Filburt, and Rocko's faithful dog Spunky.  It is set in the fictional town of O-Town.  Throughout its run, the show was controversial for its adult humor, including double entendre, innuendo, and satirical social commentary, similar to "The Ren & Stimpy Show".

Rocko: Rocko is the eponymous fictional character of the cartoon "Rocko's Modern Life" and the comic book series of the same name.  Rocko was born in Australia and emigrated to America in High School.  He was pitched to Nickelodeon executives as having the personality of a young wallaby Woody Allen.  Carlos Alazraqui provided the voice of Rocko in the television series.

Ed Bighead: Edward "Ed" Bighead is a fictional character in the cartoon series "Rocko's Modern Life" and the comic book series of the same name.  Mr. Bighead, an anthropomorphic cane toad, lives next door to the main character of the show, Rocko, whom he vehemently dislikes.  In the television show, he is voiced by Charles Adler.

Supporting paragraphs: Rocko's Modern Life Heffer Wolfe
Answer: Tom Kenny