I remember absolutely adoring this show, however, apart from the Kenneth Williams voiced robot on wheels (which I seem to recall looked a little like the centre of the Tardis from Doctor Who) I remember very little about the characters.
I recall it being fairly modestly budgeted, however, the script was really funny (although bear in mind I was only a young-un so it may well be nostalgia clouding my memory) one particular episode sticks out in my mind where the captain gets changed into a can of soft drink (for reasons I can no longer recollect) and one of the other crew accidentally drink a bit of him, when returned to human form he has permanently lost some vital part of his memories.
In conclusion, much better than Rent-A-Ghost.