The line comes from Tobias and the Half-Pariah by Tines Sensahthe, a fan-made Thomas series that reimagines the engines with darker, more dramatic stories. Montague, better known as Duck, delivers the line in an angry moment that fans clipped for its blunt, territorial tone. Once shared on soundboards, it found a second life outside the series as a reaction sound for possessive jokes, arguments over belongings, and exaggerated ownership. Its appeal lies in how instantly the emotion reads, even without knowing the original episode.