We know that Dumbledore (and McGonagall) were both Transfiguration Professors before becoming Headmaster/Headmistress.
What was Armando Dippet teaching before becoming Headmaster?
Any level of canon acceptable.
Science Fiction & Fantasy Stack Exchange is a question and answer site for science fiction and fantasy enthusiasts. It only takes a minute to sign up.
Sign up to join this communityWe know that Dumbledore (and McGonagall) were both Transfiguration Professors before becoming Headmaster/Headmistress.
What was Armando Dippet teaching before becoming Headmaster?
Any level of canon acceptable.
We don't know.
There isn't any information in the canon books, additional materials, pottermore, films, video games, frog cards or JKR's old website that tells us what he taught at Hogwarts (or even if he taught at Hogwarts) prior to becoming Headmaster.
Unless there are future revelations about him, we'll have to remain clueless on this issue.