If is a monoidal category whose tensor product preserves reflexive coequalisers in each variable, then there is a bicategory of comonoids and comodules in . An example of this is where , the category of polynomial endofunctors of , for which it turns out that is equivalent to , the bicategory of parametric right adjoint functors between presheaf categories. I figured this out in 2020 in a very hands on way; this talk is about the slick way of doing this via the paper best known around here as [18].