The appearance of comic strip characters usually evolves from the first time they are shown until a definitive look is arrived at. The early Dick Tracy, Li'l Abner and Terry Lee (of Terry and the Pirates) were but wispy hints of the boldly-drawn evolved versions familiar to comic-strip buffs and those old enough to recall their heyday.
Occasionally, a character's look never quite settles down. Consider Wilma Deering, longtime girlfriend of Buck Rogers, the pioneering space-faring comic strip hero of "Buck Rogers in the 25th Century."
The Buck Rogers strip evolved from a science-fiction magazine story, appearing in newspapers early in 1929 (the Wikipedia entry on Buck Rogers is here). The original artist was Dick Calkins, an Army Air Service pilot and flight instructor in the Great War who went on to a career as a newspaper artist.
In my judgment, Calkins was never much of an artist, and the strip probably succeeded more on the novelty and glamor of space travel and strange other worlds (along with standard-issue swashbuckling in sci-fi guise) than in the quality of Calkins' drawing.
Eventually, Calkins' imagery became fairly consistent. But in the early months of the strip, the appearance of Buck, Wilma and supporting characters varied considerably. In fact, it almost seemed like more than one artist had a hand in the strip -- though as far as we know, help in the form of Rick Yager didn't appear for another four years.
The Wikipedia entries above disagree as to when and to what degree Yager took over from Calkins. Yager had responsibility for the Sunday strips, and his style there was definitely different from that of Calkins by the 1940s. I'm inclined to agree with the Calkins entry that Calkins did the dailies as late as 1947 or so. That's based on drawing style. On the other hand, Yager was able to mimic the flowing style of "Lichty" in the Grin and Bear It cartoon, so perhaps he indeed drew dailies in the brittle idiom Calkins had evolved as the 1930s wore on.
Below are examples of Calkins' version of Wilma Deering, four from the first year of the stip, and one from ten years later.
If I have to characterize Calkins, I would call him inconsistent -- occasionally coming up with a satisfying image, but usually dishing out the level of hack-work that was acceptable to 1930s newspaper readers. This last point takes into account the average artistic competency demonstrated in adventure strips of the time. Far, far above that level was the talent exhibited by Alex Raymond (Flash Gordon), Hal Foster (Tarzan and Prince Valiant), Burne Hogarth (Tarzan) and the rapidly improving Milton Caniff (Terry and the Pirates).