The character debuted as the patriarch of the original family unit on the show, the Neilsons.

A new character, Sláine, debuted in 1983, but had been in development since 1981.

Of unknown age, the character debuted on February 25, 1993.

The character debuted on-screen during the episode broadcast on 26 January 2009.

The character debuted July 15, 1968, and continually appeared through May 28, 2004.

The character debuted on-screen during the episode airing on 5 March 2009.

The character debuted on-screen during the episode airing on 7 March 1988.

The character debuted on-screen during the episode airing on 23 July 2010.

The character debuted on-screen during the episode airing on 20 November 2008.

Around this time, a mysterious new character called Cable debuted.