  The Friedmann equations of Cotton gravity provide a simple parametrization to
reproduce, by tuning a single function, the Friedmann equations of several
extensions of gravity, such as f(R), modified Gauss-Bonnet f(G), teleparallel
f(T), and more. It also includes the recently proposed Conformal Killing
gravity and Mimetic gravity in FRW space-times. The extensions generally have
the form of a Codazzi tensor that may be associated to the dark sector. Fixing
it by a suitable equation of state accomodates most of the postulated models
that extend $\Lambda$CDM, as the Chevallier-Polarski-Lindler model.
