In On Humour, Simon Critchley suggests that ‘when the human becomes animal the effect is disgusting and if we laugh at all then it is what Beckett calls the “mirthless laugh”’ (Critchley 2002:33). In this article, I take seriously Critchley's suggestion that human-to-animal transitions are disgusting, and I seek to critically examine the nature of this disgust and its interplay with this ‘mirthless laughter’. I suggest that there are two fundamental aspects to this phenomenon that need to be disentangled. The first aspect relates to what John Limon (2000) calls the ‘not quite alienable’ aspects of ourselves – feces, urine, corpses, etc. – that social propriety demands that we hide, which can be understood in terms of Kristeva's account of the abject. (Kristeva 1982) The second aspect, I will argue, is the way in which human-animal metamorphoses act as a metaphor for disease. Drawing on Havi Carel's reading of The Fly (dir. David Cronenberg, 1986) to make this argument, I suggest that what one finds in bot...