I would have said he's in 3 eps. Besides the one the quote comes from, he's introduced in the previous one. And then down the line in the ep where Barnabas explains everything to Julia, Oberon is seen in a flashback to a scene we never saw originally when Barnabas was first indoctrinated in 1796. But I have no memory of the circumstances of the 4th one...
Complete this phrase: "Bill was stunned when he learned from Constable Carter that the fingerprints found on the wrench in Roger's car proved conclusively that...!!"
Rog: Do you know you have a mustard stain on your uniform, Constable? Carter: That’s not mustard. I hate mustard! I loathe mustard! It’s a urine stain - don't ask!