I appeared in a Yorkshire TV educational show called 'How We Used to Live' - In the UK, there was a tradition of TV stations making shows targeted at schools, for teachers to show in class. 'How We Used to Live' typically had a five to eight show format concentrating on a particular area of the History curriculum, and for the shorter runs, they would also make a two or three show 'filler', which got even lower ratings than the (already very low rated) curriculum-based shows. I was an extra in one of those 'filler' shows; I have about five seconds of airtime, as a stable hand taking a horse from which the lead actor had dismounted and leading it past the camera. That's just about the lowest you can get in TV acting while actually having your image broadcast at all.
That scene took a whole morning to film (because the actor kept fluffing his lines - the director was apoplectic, and said that next time he would ask the agency to send him an actor who could walk and talk at the same time), and was a part of a five day shoot at a rather nice Tudor moated house; I also participated in three other location shoots for the same show, but all my roles there ended up on the cutting room floor. At the time, I was only patchily employed (this was during the deep recession at the end of the 80's), and the pay was pretty good - certainly better than the labouring jobs I mostly had at the time. Better yet, we got paid from arrival at the YTV studio in the morning, until we got back in the evening, so there were several hours of pay just for sitting on a bus; And best of all, the catering on location was excellent, and free of charge, so you could fill up at lunch and not have the expense of breakfast or dinner.
I got the job because a friend of mine, who know the producer, was asked if he knew any extras who could provide their own costume, and I was at the time also doing 17th Century reenactment.
So I guess my credit would be 'Extras casting by <bilby's friend>'.