Been thinking a lot about the idea that a StarClan cat appearance becomes more fantasy-like based on the stories of them and how they're perceived by the living. So new spirits would look more like how they were alive while older spirits would look different.
[ID: A sketch of BB!Gray Wing, Patron of Wisdom, over many generations. Xeir hood has changed into the wings of two pheasants, with their eyes overlapping xeir own, and beaks crossing above the nose. Xeir body is covered in illegible script.]
While I do imagine they keep a "BE NOT AFRAID" normal-form that they can choose to appear as, yes. Over time, ancestral spirits begin to lose touch with their mortal forms and become abstractions.
Once, long ago, the Four Seasonal Gods resembled something very much like an ancient patron of Silverpelt. In comparison to Rock, Sol, Midnight, and Sharptooth, even the oldest spirit in StarClan (Gray Wing) is still an infant.
Partner and I are still designing the other founders but Gray Wing and Clear Sky are pretty solid.
[ID: A sketch of BB!Skystar, Patron of War, over many generations. He is wearing a thousand pelts stitched together like a king's robe, flowing down his body.]