The Tick was originally a comic by
Ben Edlund. This comic has spawned two
TV shows, both of which contain characters and incidents different from each other and from the comic, although the Tick and Arthur are always the
protagonists. Ben Edlund wrote on both shows, but other than that they have few people in common.
The first show was an animated cartoon which started airing in 1994 on Fox (and was later shown on Comedy Central). Townsend Coleman did the voice of the Tick, and first Micky Dolenz and then Rob Paulsen did the voice of Arthur. Numerous characters appeared who had not been in the comic books, such as fellow superheroes Sewer Urchin, American Maid, and Die Fledermaus, and three seasons totaling 36 episodes were made. Fox Children's Network, Saban Entertainment, Graz Entertainment and Sunbow Productions share the rights to the animated show.
The second show is a live-action comedy which aired on Fox evening prime-time in 2001. Barry Sonnenfeld was the major force in getting this one made through Columbia Tri-Star, which is a subdivision of Sony Entertainment. Patrick Warburton plays the Tick, and David Burke plays Arthur. Due to copyright issues, the characters created for the animated show rather than the comic cannot appear in the live-action one. Ben Edlund said, "The rule is, anything which appeared in the 12-issue comic book series I did is free from the constraints of the cartoon contract. This includes Tick, Arthur, Spoon!, and all the heroes and villains in those books." So American Maid and Die Fledermaus in the first show were replaced by Captain Liberty and Batmanuel in the new one -- the characters are similar but not exactly alike.
Sources:
us.imdb.com
http://members.aol.com/evileyecafe/faq.html
thetick.virtualave.net
http://slashdot.org/article.pl?sid=01/11/26/2219219
http://www.pazsaz.com/tick.html
www.public.iastate.edu/~rllew/chrn1994.html