Roobarb (and Custard) was written by Grange Calveley, and Produced/Directed by Bob Godfrey, who was also responsible for Henrys Cat, and Noah & Nelly.
Narrated by Richard Briers, (of The Good Life, and Ever Decreasing Circles fame) a typical episode would find a bored Roobarb (a mental green dog) inventing something pointless in his shed, much to the amusement and derision of Custard (a pink Cat) and the Birds.
See 'Roobarb & Custard Too' for the later 2005 series.