I'd guess that Blunder was David Mitchell's equivalent of the first Genesis album in that both had to start somewhere despite the results. Much better was to come from both! Karate Johnson was the best-loved character in our house, though Emperor Boswellox came close. I know someone who's just like Emperor Boswellox in that they make a big deal of getting the orders in!
I first got to know of Tony Way here as the father who keeps telling his son to shut up. Way is one of those performers whose face is recognisable whatever role he plays, though he's never had a major leading role. When I first saw him as Gary in 'Mongrels', I said to myself 'That's Emperor Boswellox'!
Nina Conti, who operated the singing cat, is another person who's done all sorts since as was Simon Farnaby, who's best known to me as George IV in Horrible Histories!