This article generates new understandings of dementia through feminist posthumanist and performative engagements with co-creative artmaking practices during a six-month study in a residential care home in Norway. Dementia emerges within multisensorial entanglements of more-than-human materials in three different artmaking sessions, which first materialized in the form of collective photographs and vignettes and culminated in a final exhibition, Gleaming Moments, in the care home. Drawing on these photographs, vignettes, and the author's engagement as a research artist in the sessions, this analysis examined how dementia was enacted as a spark of inspiration, felted warm seat pads, and a friendly more-than-human touch, that is, a touch of human and nonhuman art materials. These findings suggest new ontologies of dementia within multisensorial artmaking practices, in which dementia functions as a material for co-creative artmaking rather than a disease. These findings disrupt dominant biomedical ontologies of Alzheimer's disease and other dementias, as well as humanist person-centered practices in dementia care, which have concretized an individual, rather than relational, focus on dementia. In contrast, this study explores dementia as a phenomenon within the entanglements of human and nonhuman intra-active agencies. By highlighting the significance of these agencies (i.e., sponge holder-painting, wool-felting, choir-singing, chick-making) for different worlds-making with dementia, this study provides an entry point for imagining feminist posthumanist caring. Thus, dementia becomes a matter in life that is not to be managed and defeated to achieve successful aging, but to be interrogated and embraced.