Semper Gumbi was the motto of one of my helicopter detachments.
(Always Flexible) (If you don't recall Gumby from TV, maybe that's an American thing)
As a riff on Carpe Diem there was a guy I knew whose motto was Carpe Noctum.
His wife's "Carpe Scrotum" riposte during a squadron party got a burst of laughter from the whole room...