Hogwarts, the School of Witchcraft and Wizardry in the Harry Potter books, has the following Latin motto: Draco dormiens numquam titillandus.
Most online sources translate this as "Never tickle a sleeping dragon". However, it occurred to me that, since titillandus is a future passive participle, it should not necessarily be translated as the main verb. Additionally, draco and dormiens are both masculine, so I don't think they should be translated as the nominative subject.
I have come up with a couple of potential translations:
A sleeping dragon never to be tickled.
This does not flow very well in English however, so I was thinking that perhaps est was omitted from the motto. On the basis that est should have been included, titillandus est would then be a passive periphrastic. As a result, we could then say
A sleeping dragon is never to be tickled.
A sleeping dragon must never be tickled.
Though "never tickle a sleeping dragon" still preserves the meaning, I believe that the other translations I propose are more accurate with respect to the Latin.
I would like to know if anyone can think of other potential translations that I am missing. Furthermore, can the active equivalents of intended passive phrases as such be considered equally legitimate? Are there any other historical or modern examples of this?