Often used in the plural, "tantrum" denotes an uncontrolled outburst of anger and frustration, typically in a young child. In this paper we attempt to enact a feminist project of reclamation and reconfiguration of 'the toddler tantrum'. Drawing on a range of theoretical traditions, this paper investigates the complex yet generative possibilities inherent within the tantrum to argue that it can be encountered as more-than-human, as a worldly-becoming, and as a form of resistance to Anthropocentrism and childism. We propose that the tantrum might be reappraised as a generative form of (child) activism. By mobilising the potential of arts-based approaches to the study of childhood we seek to reach other, opened out and speculative accounts of what tantrum-ing is, what it makes possible, and what it might offer to stretch ideas about, and practices with very young children. We undertake a tentacular engagement with children's literature to arrive at possibilities to resist smoothing out, extinguishing or demonising the uncomfortable affective ecologies that are agitated by child rage. This paper brings together a concern with affect, materialities and bodies as they coalesce in more-than-human relationalities captured within 'the tantrum'. In doing so, the unthinkable, the unbearable, the uncomfortable and the unknowable are set in motion, in the hope of arriving at a (more) critically affirmative account of childhood in all its messy complexity.