Jerome debuted in StrongBadEmail: anything. Homestar thought the sender's name was Jerome, shortly after the email was read aloud.

He also appears on the Strong Bad Sings CD. He is on the national anthem. "Jerome! Jerome! Show some respect!"
and also there was (not including Jerome)"Spit that gum out!" right after the other quote.

Now what? Are we to name every emailer? Anyway Jerome didnt exist, He was dan, so obviously it was a different Jerome. -SephirothBadReligion