This essay employs the figure of the Loch Ness Monster as an anchor and an allegory for the operations of affect and appearance in contemporary performance. More specifically, I examine the dialectical relationships between the two, and explore how appearance performs when a critical project seeks to grasp reality as it exists apart from any subjective embellishments. Drawing on eyewitness accounts and continental philosophy, I claim that the Monster objectivizes a fundamental feature of subjectivity, namely the tension between appearance and reality, and that this tension is performed by the subjects who perceive it. As a performance of subjectivity, the Loch Ness Monster is simultaneously dependent on and exists independently of its material context. This analysis poses a challenge and a reminder to theatre and performance studies, where the possibility of affect being inherent to the contradictory relationship between appearance and reality must be fully accounted for in theoretical terms.