Raise the sails, mateys!

A Dimetrodon grandis stretching out after a good nap.
Drawn because my most recent Dimetrodon reconstruction was one of those half-sail/no-sail abominations. Always check your sources!

So here's a pelycosaur with only the tips of its spines naked, a short tail and a more mammal-like spinal collumn but you can't see the latter.
As for why there's this article from that I suggest you to read in case you hadn't already. Half-sail Dimetrodon reconstructions are a plague that needs to be dealt with...
The belly and tail are covered in scutes while the rest of the body is naked skin. Decided to not put fur on it.
A part of its sail is bitten off, but there are also lots of scars in its face, based on how modern predators have a lot of those too as explained in this video.
Finally, there's an ugly, mostly healed wound on its left front limb by a Xenacanthus because Dimetrodon are known to have hunted sharks.